Herein, benzophenone hydrazone derived two It-conjugative networks viz. DMHMN and DMHMP have been judiciously designed for competitive recognition of F-- (LOD: 6.8 ppm; Ka: a : 7.2 x 103 3 M- 1 ) over CN-- (LOD: 0.3 ppm; Ka: a : 20.3 x 104 4 M- 1 ) along with Cu2+. 2+ . Interestingly, the presence of an extra phenyl ring in DMHMN played a pivotal role for discriminative colorimetric recognition of F-- over CN-- despite having greater hydration energy of F-- . Deliberate implantation of an extra phenyl ring leads to enhanced acidity of the benzophenone platform, rationalizing structure-performance synergies. While the presence of dangling - OH group and azomethine functionality enables both the chemosensors to exhibit selective recognition toward Cu2+ 2+ in purely aqueous phase with the detection limit of 0.7 ppm and 0.16 ppm by DMHMP and DMHMN respectively, which are far below the safe limit set by World Health Organization (WHO). The sensing phenomenon by the redox non- innocent sensory receptors has been thoroughly investigated by UV-Vis, cyclic voltammetry and 1 H NMR spectroscopic studies validated by density functional theory (DFT). Moreover, relay recognition of Al3+ 3+ by [DMHMN & sdot;F-] DMHMN & sdot; F- ] ensemble made it a suitable contender for complex logic circuitry fabrication like IMPLICATION/ INHIBIT circuit. Additionally, the sensory probes have the capability of quantitative estimation of Cu2+ 2+ from unknown water samples, which was cross-examined with the help of the lab-based market available portable device. Lastly, smartphone assisted point-of-care testing (POCT) application has been performed for on-field detection of F-- by DMHMN. .

Nerve agents are used as lethal chemical weapons for terrorist activities due to their imperative neurotoxic effects to mankind. Owing to the diverse varieties in organic linkers, metal nodes, porosity along with impressive thermal/aqueous phase stability, robustness, metal organic frameworks (MOFs) are excellent candidates for effectual detection as well as degradation of neurotoxic nerve agents. In the present chapter, we have discussed the brief history of nerve agents along with their life-threatening toxicological effects. The strategic advancement of the MOFs based research works on detection as well as detoxification of the nerve agents as well as nerve agent simulants has been systematically overviewed. Ultimately, the gaps of the current research endeavor along with future perspectives have also been outlined.

Reactive sulfur, oxygen and nitrogen species (reactive SON species) are important topics in redox biology and their recognition by rhodamine-derived probes is impactful in the bio-medical research field.

Herein, a homobimetallic azomethine-functionalized nickel(II) complex, [Ni2L2(van)(mu(1,1)-NCS)] (AMR-1, where L = 2-[(2-Hydroxy-1,1-dimethyl-ethylimino)-methyl]-6-methoxyphenol, molecular weight = 788.20 (found)) has been judiciously synthesized with N-coordinated end-on thiocyanate. AMR-1 exhibited promising chromogenic variation from pale green to colourless with hypochromic shifting in the visible region in the presence of silver(I). Herein, the exposed sulfur site of the co-ligand acts as chemodosimetric recognition site for highly selective detection of a soft metal pollutant, silver ion (Ag+) with the limit of detection (LOD) of 0.37 ppm. Along with this, aqueous cyanide (CN-) recognition was accomplished in a mutually independent way with distinct chromogenic variation from pale green to yellowish color within similar to 5 s. This led to the LOD of 0.46 ppm, which is much lower than the safe limit, set by the World Health Organization (WHO). The stability constant value for cyanide interaction with AMR-1 is obtained to be 1.49 x 10(3) M-1 as per 1:1 binding stoichiometry. Experimental findings, obtained from UV-Vis, HR-MS, FT-IR, and H-1 NMR spectroscopic studies in conjugation with the decreased HOMO-LUMO energy gap from 3.40 eV to 2.07 eV, obtained from density functional theory studies, support the mechanistic pathway of interaction. Implementing molecular logic platforms benefits from fabricating three-input-two-output logic circuits by imitating variable spectroscopic outcomes. Real-time multifarious applications of AMR-1 have been accomplished with paper strip-based solid-state assay and recognition of the target-specific analytes from targeted medicinal specimens and from both cyanogenic as well as non-cyanogenic food sources. To the best of our knowledge, this is probably the first nickel(II) complex derived sensory receptor that is effectually implemented towards recognition of another metal ion, silver (I) along with CN- from aqueous as well as from real specimens.

Herein, benzophenone hydrazone derived two π-conjugative networks viz. DMHMN and DMHMP have been judiciously designed for competitive recognition of F− (LOD: 6.8 ppm; Ka: 7.2 × 103 M−1) over CN− (LOD: ∼0.3 ppm; Ka: 20.3 × 104 M−1) along with Cu2+. Interestingly, the presence of an extra phenyl ring in DMHMN played a pivotal role for discriminative colorimetric recognition of F− over CN− despite having greater hydration energy of F−. Deliberate implantation of an extra phenyl ring leads to enhanced acidity of the benzophenone platform, rationalizing structure-performance synergies. While the presence of dangling OH group and azomethine functionality enables both the chemosensors to exhibit selective recognition toward Cu2+ in purely aqueous phase with the detection limit of ∼0.7 ppm and ∼0.16 ppm by DMHMP and DMHMN respectively, which are far below the safe limit set by World Health Organization (WHO). The sensing phenomenon by the redox non-innocent sensory receptors has been thoroughly investigated by UV–Vis, cyclic voltammetry and 1H NMR spectroscopic studies validated by density functional theory (DFT). Moreover, relay recognition of Al3+ by [DMHMN·F−] ensemble made it a suitable contender for complex logic circuitry fabrication like IMPLICATION/INHIBIT circuit. Additionally, the sensory probes have the capability of quantitative estimation of Cu2+ from unknown water samples, which was cross-examined with the help of the lab-based market available portable device. Lastly, smartphone assisted point-of-care testing (POCT) application has been performed for on-field detection of F− by DMHMN.

The presence of metallic adulteration even in very trace level may lead to deleterious impact on the biodiesel quality and ultimately may be responsible for the dropping down of system efficiency, which necessitates the trace level recognition of heavy metal adulteration from biodiesel. In this context, herein using an azomethine functionalized chromogenic chemoreceptor, 1-((E)-(4-hydroxyphenylimino) methyl) napthalen-2-ol (HMN) has been reported for the selective chemodosimetric recognition of Cu2+ with a lower detection threshold of 7.8 ppb via distinct chromogenic variation of HMN. In addition to this, it has also exhibited selective and reversible naked eye chromogenic sensing behaviour towards F- (LOD=160 ppb) and Al3+ (LOD=48 ppb) at very trace level, which is quite lower than the WHO permissible limit. Distinct chromogenic recognition of F- by HMN proceeds via strong intermolecular hydrogen bonding mediated improved intramolecular charge transfer. The spectroscopic response of HMN in alternate presence and absence of the targeted analytes made it suitable to formulate AND-NOT-XNOR-NAND-OR gate based 'Castle-like' complicated logic circuitry. In-vitro cell imaging study using A549, human lung carcinoma cell line attests intracellular recognition capability of HMN, demonstrating its effectual bio-medicinal applications. Interestingly, inspired by the capability of HMN towards recognition of copper from biodiesel specimen, an RGB-assisted device comprised of TCS color sensor and an Arduino UNO 8-bit microcontroller has been developed for real-time quantitative analysis of the biodiesel adulteration. Going one step further, utilization of lab-on-a-box based prototype to monitor the concentration-dependent chromogenic fluctuation via RGB analysis is undoubtedly beneficial for the determination of copper adulteration in biodiesel sample. The presently developed chemoreceptor can thus be regarded as a valuable addition in the field of supramolecular chemistry as well as a significant initiative towards regular monitoring of the biodiesel quality control parameters as a part of sustainable environment.

Optical nanoprobes for biosensing applications have gained widespread attention for recognition of a variety of biorelevant ions or molecules present in human body. In the present chapter, the nanoprobes are classified into four categories: zero, one, two, and three-dimensional nanomaterials and herein the nanomaterials include carbon quantum dots (CQDs), graphene quantum dots (GQDs), semiconductor inorganic quantum dots (IQDs), polymer dots (PDs), gold nanoparticles (AuNPs), silver nanoparticles (AgNPs), upconversion nanoparticles (UCNPs), magnetic nanoparticles (MNPs) for 0-D, carbon nanotubes (CNTs), gold nanorods (AuNRs), silicon nanowires (SiNWs), nanofibers and nanoribbons for 1-D, MnO 2 nanosheets, 2-D MOF nanosheets, graphitic carbon nitride, graphene oxide (GO), reduced graphene oxide (rGO) for 2-D and hybrid nanoflowers (HNFs) and 3-D MOFs for 3-D nanomaterials. The chapter briefly covers diverse nanomaterials and nanocomposites and their applications in chromo-fluorgenic biosensing applications. Furthermore, the applications of the nanoprobes for targeted analytes recognition from complicated biological samples as well as in intracellular imaging have also been discussed. Finally, the loopholes of the present research and future directions of the research are also enlightened to keep an ample footstep in the domain of medical diagnosis.

Excessive accumulation of As(III) in the human body may lead to severe physiological disorder including cancer as it is considered to be Group 1 human Carcinogen. There are numerous research works carried out throughout the decades for the recognition of this lethal analytes. In the present review, chromo-fluorogenic sensory receptors reported in the last decade toward recognition of As(III) have been extensively discussed. As(III) sensing mechanisms have been broadly classified into several categories including non-covalent interaction, aggregation induced emission (AIE), metal coordination, metal extrusion strategy, metal complex based probe and reaction based approach. Ultimately, the gaps of the present research strategies along with future research endeavor have also been highlighted.

Sweat contains a broad range of important biomarkers, which may be beneficial for acquiring non-invasive biochemical information on human health status. Therefore, highly selective and sensitive electrochemical nanosensors for the non-invasive detection of sweat metabolites have turned into a flourishing contender in the frontier of disease diagnosis. A large surface area, excellent electrocatalytic behavior and conductive properties make nanomaterials promising sensor materials for target-specific detection. Carbon-based nanomaterials (e.g., CNT, carbon quantum dots, and graphene), noble metals (e.g., Au and Pt), and metal oxide nanomaterials (e.g., ZnO, MnO2, and NiO) are widely used for modifying the working electrodes of electrochemical sensors, which may then be further functionalized with requisite enzymes for targeted detection. In the present review, recent developments (2018–2022) of electrochemical nanosensors by both enzymatic as well as non-enzymatic sensors for the effectual detection of sweat metabolites (e.g., glucose, ascorbic acid, lactate, urea/uric acid, ethanol and drug metabolites) have been comprehensively reviewed. Along with this, electrochemical sensing principles, including potentiometry, amperometry, CV, DPV, SWV and EIS have been briefly presented in the present review for a conceptual understanding of the sensing mechanisms. The detection thresholds (in the range of mM–nM), sensitivities, linear dynamic ranges and sensing modalities have also been properly addressed for a systematic understanding of the judicious design of more effective sensors. One step ahead, in the present review, current trends of flexible wearable electrochemical sensors in the form of eyeglasses, tattoos, gloves, patches, headbands, wrist bands, etc., have also been briefly summarized, which are beneficial for on-body in situ measurement of the targeted sweat metabolites. On-body monitoring of sweat metabolites via wireless data transmission has also been addressed. Finally, the gaps in the ongoing research endeavors, unmet challenges, outlooks and future prospects have also been discussed for the development of advanced non-invasive self-health-care-monitoring devices in the near future.

Herein, two novel mononuclear transition metal Zn2+ complexes i.e. [Zn(HL)(N3)(OAc)] (NS-1) & [Zn(HL)2(ClO4)2] (NS-2) have been synthesised using a tridentate clickable Schiff base ligand, HL (2-methyl-2-((pyridin-2-ylmethyl)amino)propan-1-ol), and the polyatomic monoanions N3- and ClO4- for NS-1 and NS-2 respectively. Interestingly, NS-1 and NS-2 have been explored for the detection of Cu2+ with an LOD of 48.6 fM (response time ∼6 s) and 2.4 μM respectively through two mutually independent pathways that were studied using sophisticated methods like UV-Vis, cyclic voltammetry, ESI-MS etc. with theoretical DFT support. Herein, both chemosensors are equally responsive towards the detection of Cu2+ in aqueous as well as other targeted real field samples with appreciable recovery percentage (74.8-102%), demonstrating their practical applicability. Moreover, the detection of unbound Cu2+ in a human urine specimen was also analysed which may be helpful for the diagnosis of Cu2+-related disorders like Wilson's disease. Taking one step ahead, TLC strips have been employed for on-field detection of the targeted analytes by contact mode analysis. Additionally, the anti-cancer activity of these complexes has also been studied on breast cancer cells with the help of the MTT assay. It has been found that at a 0.5 mM dose, both NS-1 and NS-2 could kill 81.4% and 73.2% of cancer cells respectively. However, it has been found that NS-1 destroys normal cells together with cancer cells. Hence, NS-2 could be administered as a better anticancer drug for MDA-MB-231 cancer cells in comparison with NS-1. In a nutshell, the present work describes how anion-directed synthesis of two architecturally different metal complexes leads toward the detection of the same analyte via an independent chemodosimetric pathway along with their anti-cancer activities on breast cancer cells.

Towards exploration of one-to-two unimolecular system, the applicability of a fluorescence silent Ni(II) based chemosensor, AR-1 comprised of NO2 donor Schiff base ligand towards "turn on" chromo-fluorogenic recognition of F- and Zn2+ over Cd2+ via mutually independent pathways has been unveiled in the present work. The sensing phenomenon is very fast within-18 sec for Zn2+ and-24 sec for F- with the emergence of bright greenish cyan and yellowish green coloured fluorescence respectively. The detection threshold values were acquired to be 1.3 mu M (388 ppb) for Zn2+ and 3.4 mu M (887 ppb) for F-. UV-vis, fluorescence, mass spectroscopic and electro-chemical investigation with theoretical DFT and TDDFT studies support the chemodosimetric sensing phenom-enon. AR-1, characterized by single crystal X-ray data, is equally responsive towards solid state sensing of the targeted analytes. Moreover, it has also been employed towards preparation of three-input-two-output logic cir-cuitry, which is unique of its kind in the relevant domain. Most interestingly, to the best of our knowledge, AR-1 is the first Ni(II) based Schiff base chemoreceptor, which has been effectively implemented for real-time detection of Zn2+ from complex bio-matrix, like serum upto 1.83 mu M (544 ppb). This may give an indication of copper deficiency myelopathy (CDM), of which early diagnosis may reduce the risk of irreversible neurological damage.

Regular monitoring of H2PO4- is inevitable owing to its physiological, chemical as well as environmental significance. Herein, a new and promising azophenine-functionalized Zn2+ complex, CN-1 center dot Zn2+ is rationally designed for the selective and sensitive colorimetric detection (LOD = 67.9 ppb) of monophosphorylated species, H2PO4- based on H2PO4- -specific metal-extrusion assay through hypsochromic shift in the UV-vis spectra. The sensing phenomenon has been authenticated via UV-vis, ESI-MS, CV, LSV, H-1 NMR studies with theoretical (DFT) substantiation. CN-1 center dot Zn2+ has been exploited towards two-input-two-output logic circuitry fabrication, advantageous for molecular-level information storage. Moreover, TLC strip-based contact mode analysis is beneficial for its on-spot applicability. Smartphone-assisted chromogenic recognition efficiency of CN-1 center dot Zn2+ via RGB analysis has been well-correlated with spectrophotometric outcomes, demonstrating reliability of the present method. Phosphate detection efficacy of CN-1 center dot Zn2+ in serum specimens with qualified recovery (90.9-98.9 %) makes it a potential diagnostic tool for monitoring chronic kidney disease (CKD). Additionally, CN-1 center dot Zn2+ exhibited DNA binding activity through non-intercalation mode, examined via UV-vis, fluorescence spectroscopic studies with in silico docking. This is the first Zn2+-complex in azophenine family, effectively employed for smartphone-assisted phosphate detection having promising DNA-binding activity, thereby leaving a sustainable footprint in the domain of supramolecular and bio-medical functional world of applications.

A new Ni2+ complex of an azophenine-based sensory receptor, CN-1•Ni2+ is judiciously designed for selective aqueous phase fluoride recognition based on specific hydrogen bonding interaction with sharp chromogenic variation from brownish orange to purple. The mechanistic pathway of interaction has been thoroughly investigated via ESI-MS, FT-IR, differential pulse voltammetry (DPV) studies with theoretical DFT support and Loewdin spin population analysis. The detection limit was acquired to be 148 ppb, which is lower than the WHO permissible limit. The real-time sensitivity of the probe has been displayed by TLC strip-based solid-state sensing assay. The probe is also responsive towards recognition of fluoride from various real field water specimens with promising recoveries (95–119%). One step ahead, the chemically obtained outcomes have been extensively synchronized with electronic circuitry to fabricate lab-on a-box based Layman's prototype for on-spot, decentralized detection of fluoride, which would be beneficial for the end users, particularly in the fluoride endemic areas. Moreover, based on the reversible spectroscopic outcome, herein AND-NOT-OR-NOR gate-based complex logic circuitry and sequence-dependent molecular keypad lock has been fabricated. In addition, silica gel supported composite material, CN-1•Ni2+@SG has been prepared for effectual remediation of aqueous fluoride below safe limit. Thus, the present work relies on recognition as well as proficient remediation of aqueous fluoride based on selective tuning of acidity, validating the 'Two-in-one' approach.

Herein, we have designed a new Co(II)-based MOF, {[Co(1,4-NDC)(4,4 '-BPY)(H2O)(2)].H2O}(infinity) (Co-NDC-BPY) by using mixed ligands 1,4-napthalenedicarboxylic acid (1,4-NDC) and 4,4 '-bipyridine (4,4 '-BPY). Interestingly, the MOF can selectively and discriminatively detect S2- and HSO4- from purely aqueous medium via mutually independent mechanism with prompt response (similar to 6 s) at very low detection thresholds of 29.9 mu M and 9.4 mu M for S2- and HSO4-, respectively. In the presence of S2-, "turn-off" fluorescence response is perceived via static quenching due to facilitation of photoinduced electron transfer (PET) process via ground state complexation. On the other hand, protic anion, HSO4- systematically enhanced the fluorescence at 435 nm via releasing the co-ligand. Moreover, detection from several field-water samples with good recovery, demonstrates the real-world applicability of this Co-NDC-BPY MOF. To the best of our knowledge, this is the first MOF based chemosensor, which could discriminatively detect HSO4- and S2- from fully aqueous solutions. Additionally, this MOF exhibits excellent catalytic activity in the CO2 fixation on epoxides. The potential energy calculation suggests the possible mechanistic pathway for this cycloaddition reaction. As it possesses a moderately low band gap with n-type conductivity, this Co-NDC-BPY MOF is also explored as photocatalyst in thiol-ene chemistry for the synthesis of thiol-ether bridged bis-carbonate from allyl-glycidyl carbonate monomer, which is a platform chemical for the synthesis of valuable polymers.

The ratio of GSSG to GSH plays a key role as a biomarker for monitoring cellular health thus fuelling extensive ground-breaking research towards the development of robust sensory receptors for continuous monitoring of glutathione concentration.

A regioselective synthetic strategy for 6-aryl-8,9-dihydrobenzo[c]phenanthridine-10(7H)-ones (4) is accomplished using a one-pot four-component reaction by fine-tuning the reaction temperature. DMSO is excellently used as a reactant-cum-solvent to introduce a carbonyl functionality regioselectively at the C-10 position of the benzophenanthridine backbone, via an MCR, which is unknown yet. The elegant features of this strategy are the formation of two CC, one CN, and one CO bonds in a single step, without using a base and an activator for the oxygenation process. Then, a few compounds (4) are easily aromatised to achieve 6-arylbenzo[c]phenanthridin-10-ol derivatives (7) using I2/DMSO at 100 °C. Nay, a dangling hydroxyl group in 4s, 4u, 4x, and 4z helped them to be employed as promising 'naked eye' colorimetric chemosensors for fluoride with limits of detection of 0.65, 0.60, 0.34, and 2.2 ppm, respectively. Moreover, the reversibility of the chemosensors makes them suitable for combinatorial INHIBIT logic gate formulation. The compounds have also been employed for solid-state F- detection via the spot TLC test.

We report a Ni-MOF (nickel metal-organic framework), Ni-SIP-BPY, synthesized by using two linkers 5-sulfoisophthalic acid (SIP) and 4,4'-bipyridine (BPY) simultaneously. It displays an orthorhombic crystal system with the Ama2 space group: a = 31.425 Å, b = 19.524 Å, c = 11.2074 Å, α = 90°, β = 90°, γ = 90°, and two different types of nickel(II) centers. Interestingly, Ni-SIP-BPY exhibits excellent sensitivity (limit of detection, 87 ppb) and selectivity toward the 2,4,6-trinitrophenol (TNP)-like mutagenic environmental toxin in the pool of its other congeners via "turn-off" fluorescence response by the synergism of resonance energy transfer, photoinduced electron transfer, intermolecular charge transfer, π-π interactions, and competitive absorption processes. Experimental studies along with corroborated theoretical experimentation, vide density functional theory studies, shed light on determining the plausible mechanistic pathway in selective TNP detection, which is highly beneficial in the context of homeland security perspective. Along with the sensing of nitroaromatic explosives, the moderately low band gap and the p-type semiconducting behavior of Ni-SIP-BPY make it suitable as a photoanode material for visible-light-driven water splitting. Highly active surface functionalities and sufficient conduction band minima effectively reduce the water and result in a seven times higher photocurrent density under visible-light illumination.

Cu 2+ and CN − detection by chromo-fluorogenic probes with insight of photophysical signaling mechanisms has been systematically discussed. Exquisite integration of chemical response with RGB mediated electronic sensing prototype have been summarized.

An azophenine derivative based copper complex (CN-1 center dot Cu2+) is rationally designed and unveiled herein for the first time in the realm of azophenine family, which can selectively detect cyanide from purely aqueous medium via metal-displacement approach (MDA). CN-1 center dot Cu2+ exhibits 'naked-eye' chromogenic change from brown to yellow with corresponding hypsochromic shift in UV-Vis spectra having detection threshold of 0.23 mu M (60 ppb) which is far below the permissible limit of CN- in drinking water set by WHO. The mechanistic course of interaction has been affirmed by experimental evidence with theoretical corroboration. A one-to-two decoder logic circuit has been formulated based on the selective recognition phenomenon. CN-1 center dot Cu2+ can also monitor CN- in a series of environmental samples, wherefrom CN- could be recovered at an appreciable quality rate (similar to 99.4-101.1%), escalating the real-field applicability of the developed material. Interestingly, the complex also exhibits efficacy towards recognition of endogenous cyanide from cyanogenic food sources like sprouting potatoes, bitter almonds. Moreover, CN-1 center dot Cu2+ is equally responsive toward real-time monitoring of cyanide in different physiological samples, like blood plasma, serum with appreciable intracellular fluorescence imaging capability examined on HeLa and Candida albicans cell lines, which unambiguously could be a potential tool for autopsy investigation in cyanide-induced death cases. This is the first azophenine-based copper complex, which exhibited significant anti-bacterial activities on Bacillus subtilis and Escherichia coli, anti-mycotic activities on Candida albicans and also in-vitro anti-cancer activities on cervical cancer cell lines (HeLa).

In real day scenario, it is an urge to provide a single solution of multiple problems. In this regard, herein rapid, selective and highly efficient chromo-fluorogenic detection of ammonia/aliphatic amines over aromatic amines has been investigated by means of a novel "opto-electronic nose ", CN-2, synthesized in a single-step via multiple inter/intramolecular C-N fusion reactions. The in-situ generated monoprotonated CN-2 can selectively detect primary to secondary to even tertiary aliphatic amines over aromatic amines within similar to 40 S with extremely low detection threshold values of 27.2 ppb, 0.7 ppm, 5.4 ppm, 1.7 ppm from UV-Vis and 42.5 ppb, 1.61 ppm, 5.5 ppm, 6.14 ppm from fluorescence spectral data for NH3, hydrazine (primary amine), diethanolamine (secondary amine) and triethylamine (tertiary amine) respectively with the hypsochromic shift in the UV-Vis spectra along with fluorescence attenuation via target-specific deprotonation. The colorimetric signal can also be examined by Smartphone APP, which is well correlated with spectrophotometric outcomes. Interestingly, due to presence of a unique protonated antenna centre CN-2 with anti-oxidant activity can also detect aliphatic biogenic amines, like putrescine, spermidine, which are frequently released from spoiled food. Therefore, it may be exploited as smart food-spoilage indicator in real-time. Again, the aliphatic biogenic amines recognition capability from human urine made it as a potential prostate cancer biomarker sensor for clinical use, which alleviates the need of biopsies. CN-2 could also be employed towards one-to-two decoder logic-circuitry formulation to monitor the ammonia levels. Moreover, CN-2-functionalized hydrogelmembrane based portable, handy prototype could be utilized for easy on-site recognition of amine vapour. Reversible sensing behaviour in presence of HCl enables CN-2 to exhibit anti-counterfeiting activity. To the best of our knowledge, this is the first all-in-one phenazine-based Smartphone-assisted chromo-fluorogenic-chemosensor, which would be of enormous interest in food-packaging industry, information technology as well as in early-stage-cancer diagnosis. (c) 2022 Elsevier B.V. All rights reserved.