Chronic wounds cause a significant healthcare challenge, often requiring long-term therapeutic interventions such as Negative Pressure Wound Therapy (NPWT). Matrix Metalloproteinases (MMP-2 and MMP-9) play a crucial role in wound healing, making their quantification a valuable prognostic marker for monitoring therapeutic outcomes. Herein, an external-mediator-free electrochemical immunosensor based on an in-situ redoxspecies ferrocene modified disposable screen-printed electrode (SPE) matrix for the sensitive and specific detection of MMP-2 and MMP-9 in wound exudate samples from patients is devised. Cyclic voltammetry revealed the 1e- transfer reaction of fabricated sensor in phosphate buffered saline, following a quasi-reversible behaviour at the electrode-electrolyte interface. Activation layer enabled functionalization of selective antibodies on the sensor platform, facilitating direct immunosensing of MMP-2 and MMP-9, without the need for additional labelling agents. Differential pulse voltammetry technique based immunosensing of MMP-2 and MMP-9, achieving a limit of detection in 0.19 fg/mL and 0.17 fg/mL, respectively. To support the specificity and binding affinity of the antibody-antigen interactions, microscale thermophoresis (MST) analysis was conducted, enabling dissociation constants (Kd) of 1.10686 & times; 10- 7 for MMP-2 and 4.88078 & times; 10-10 for MMP-9, indicating high-affinity binding essential for sensitive detection. Chronic and acute wound exudate samples, after standardized pre-processing, were tested using the prepared immunosensor platform and validated with ELISA, demonstrating its potential for point-of-care applications in personalized wound management.

Bilastine (BIL), a second-generation antihistamine widely used for the treatment of allergic disorders, undergoes direct oxidation through its piperidine-based tertiary amine leading to rapid electrode surface deactivation, limiting its applicability in conventional electrochemical sensing. Herein, we report for the first time an exogenous coreactant-free electrochemiluminescence (ECL) strategy in which BIL acts as an intrinsic enhancer of the anodic ECL emission of tris(2,2'-bipyridine)ruthenium(II) ([Ru(bpy)3]2+), eliminating the need for external coreactants such as tripropylamine (TPrA). Interestingly, continuous potential cycling results in an anomalous increase in ECL intensity, accompanied by a decrease in oxidation current, highlighting a unique decoupling between faradaic and luminescence response. Spectroscopic and electrochemical investigations attributed this behaviour to the formation and adsorption of a benzimidazole-based oxidative byproduct that induces partial electrode surface deactivation and facilitates a catalytic ECL pathway, leading to enhanced and stable emission. Leveraging this phenomenon, a highly sensitive ECL flow injection analysis (ECL-FIA) platform was developed, exhibiting two linear detection ranges for BIL with limits of detection of 0.162 μM and 2.22 μM, respectively. The proposed strategy offers a novel paradigm in designing of self-enhanced ECL systems where partial surface deactivation is harnessed to improve ECL performance, enabling reliable detection of electrochemically challenging small-molecule drugs.

Human papillomavirus type 16 E6 oncoprotein is a clinically significant biomarker for cervical cancer because its persistent expression drives malignant transformation. To address the need for ultrasensitive detection of oncogenic HPV16 E6 protein, we engineered an electrochemical immunosensor based on methylene blue-functionalized hexagonal boron nitride (BN-MB) nanosheets deposited on screen-printed carbon electrodes. In this architectonic design, exfoliated h-BN provides a high-surface-area support, while the π-π-stacked cationic dye methylene blue acts as an internal redox mediator, converting intrinsically insulating h-BN into an electroactive matrix. Protein G was immobilized to orient monoclonal anti-E6 antibodies in a tail-on configuration, thereby enhancing antigen accessibility. Under optimized conditions, square-wave voltammetry showed a wide linear range from 1 fg mL⁻¹ to 1 ng mL⁻¹, with an ultralow limit of detection of 0.80 fg mL⁻¹ using the 3σ/m method and a limit of quantification of 2.67 fg mL⁻¹. Zeta potential measurements and FTIR analysis confirmed strong electrostatic and π-π interactions between MB and h-BN, while MB loading was determined by UV-vis absorbance. The immunosensor exhibited excellent selectivity against a panel of interferents, including E7 oncoprotein, SCCA, CEA, and CA-125, high stability with approximately 87

Bioactives from sustainable sources like seaweed offers enormous advantages than land-based biomass due to its natural abundance, rapid growth, and low lignin content. Herein, the marine algal biomass Ulva compressa is used for the extraction of industrially important bioactives, cellulose and Chlorophyll a. Functional transformation of bulk cellulose into cellulose nanocrystals including water dispersible membrane application have been established. Studies on optical absorbance, emission, reactive oxygen scavenging function, redox behavior at the electrode-interface, anti-bacterial property and bioconjugation with alginate beads enabled that Chlorophyll a could be a multifunctional probe for biomedical application. These findings not only provide selective recovery protocols and processing of bioactives from Ulva compressa (U. compressa) biomass but also enable value added product application for the marine phycocolloids in diversified fields.

Development of a label-free biomolecular sensor probe without complex pre-treatment offers potential for advanced point-of-care clinical diagnosis. This study explores the kinetic and thermodynamic interactions between fluorophore sulfur-doped graphitic carbon nitride (S-g-C3N4) and the analyte bilirubin (BIL). S-g-C3N4 was synthesized through a green approach using thiourea as the source of sulfur and nitrogen. S-g-C3N4 exhibits strong blue fluorescence emission at 439.46 nm, with a purity of 67.12%. The addition of target BIL leads to selective fluorescence quenching without the need for an external label, following a synergistic static and dynamic mechanism. Static quenching occurs due to the formation of a ground-state complex through hydrogen bonding. Dynamic quenching is indicated by a reduction in the excited-state lifetime, which decreases from 2.17 ns to 1.71 ns. The probe demonstrates admirable sensitivity for BIL detection across a range of 0.04-70 µM, with a detection limit of 0.0256 µM. It performs reliably in both synthetic and real human urine samples. The practical applicability of the prepared fluorescence probe was further visualized by human fingerprint imaging. These comprehensive analyses substantiate the design of a highly selective method for BIL detection that can be customized as a simple, non-invasive, and stable diagnostic probe for biomolecular recognition.

Menstrual hygiene is of greater concern globally as it entirely depends on individual’s personal choice, socioeconomic status, proximity to resources, education, and cultural beliefs. The global feminine hygiene products market size was valued at USD 43.25 billion in 2024 and the market is anticipated to grow at CAGR of 6.98

Strontium oxide (SrO) and polyphenol-based research on bone health, tissue engineering, anti-oxidant and antiinflammatory are available in literature, yet the opto-electrochemical characteristics of SrO incorporated with polyphenol-derived from fungus (mushroom metabolite, Hispidin) remains unexplored. Here, we report the solvothermal-mediated synthesis of SrO nanoparticles and its surface modification with Hispidin (His) via PEGylation using ultrasonochemical process. As synthesized SrO-PEG/His exhibit absorption bands at 290 and 369 nm ascribed to pi-pi* and n-pi* transitions, respectively. Photoluminescence study of SrO-hybridized Hispidin shows a visible light emission band centered at 427 nm, enabling a blue shift from the pristine Hispidin. FT-IR spectral analysis confirmed the occurrence of interaction between C--O functional group of Hispidin and PEGylated SrO. Electron and atomic force micrograph suggest the formation of nanoscale particles with an average particle size distribution of 50 nm and roughness factor of 0.89 nm, respectively. Electron paramagnetic resonance spectral analysis affirmed that SrO-PEG/His exerts a dosage dependent (0.1 to 1 mg/mL) radical scavenging activity against standard free radical. Preliminary electrochemical studies, from cyclic voltammetry, on SrO-PEG/His modified glassy carbon electrode suggest the quasi-reversible redox behavior, following 2e-/ 2H+ transfer at the electrode-electrolyte interface. Observed results ensured that the opto-electrochemical characteristics of the synthesized nanobiohybrid system are useful for antioxidant and sensor probe construction, paving the way for futuristic applications in theranostics.

According to global health metrics, clinical symptoms such as cellulitis and pyoderma associated with skin diseases are a significant burden worldwide, affecting 2.2 million disability-adjusted life years in 2020. There is a strong correlation between the commensal bacteria and the host immune system. Classical methods deployed in dermal biofilm crosstalk studies often hamper many individuals from early diagnosis and rationalized therapy. Herein, the present report aims to study the role of skin microbiota and mechanisms of microbial crosstalk with host immune system. The emerging analytical tools devised for sensor/biosensor platforms, including molecularly imprinted polymers, microarrays, aptamers, CRISPR-cas9, and optical/electrochemical approaches, are discussed as alternative methods for important biomarker analysis. Further, the types and characteristics of microorganism-derived macromolecules and the recent skin organoid toward personalized therapy are highlighted. This information will largely benefit researchers involved in the pathophysiology of skin disease, wound dressing materials, including diagnostic and healing patch designs, in addition to biological macromolecules devoted to wound repair.

Simple method for monitoring the therapeutic efficient concentration of anti-histamine drug, bilastine (BIL), is essential for rationalizing allergy and respiratory therapy. Herein, an external redox-mediator free molecular trafficking approach was developed using conjugated oligosaccharide-polyphenol system, β-cyclodextrin-butein (BCD-Bt). Mechanism behind the molecular loading of BIL within the hydrophobic cavity of BCD simultaneously enabling the redox-active signal transduction from the conjugated Bt are explored using cyclic and differential pulse voltammetric analyses. BCD-Bt sensor platform exemplified the selective loading of analyte BIL with a reliable detection linearity (nm to μM, R2 = 0.981) and limit feasible for salivary therapeutic drug monitoring. Synergistic optical absorbance and emission-based molecular trafficking test further complements the multi-modal functionality of the demonstrated BCD-Bt in other similar molecular assays.

Brown algal extracts contain rich amount of phloroglucinol-based polyphenolic compounds called phlorotannins (PTs) which have diverse functional properties. Quality control and assurance of mixed polyphenols particularly from marine algal extracts is a complex process. Electrochemical fingerprinting is recently emerging as potential alternative for structural elucidation of natural products. In this work, we attempt to electrochemically fingerprint the isolates of marine algae, Sargassum wightii. Cyclic voltammograms of both extracts enabled irreversible oxidation peaks associated to phloroglucinol structure, following 1e−/1H+ transfer under phosphate buffered saline electrolyte. The optical activity of the electrophoretically separated phloroglucinol constitute negligible pigment traces than solid-liquid extracted sample. Drop-casted and electrophoretically-modified phloroglucinol solid surface shows their promising application for optical / electrochemical sensor application.

Electrochemical grafting of gallic acid with chitosan (EgGC) voltammetrically deposited on a multitude of substrates exhibiting reversible oxidoreduction suitable for sensor construction is reported. A bioreceptor customized from the fragment antigen binding region of SARS-CoV-2 neutralizing antibodies immobilized on an EgGC matrix supported the selective/specific electrochemical signal transduction with respect to different viral loads (femtogram level) of SARS-CoV-2.

Biocompatible, industrially scalable, and opto/electrochemically active biomaterials are promising for biosensor platform design and application. Herein, cyclic oligosaccharide, beta-cyclodextrin (BCD), is conjugated with Butein, a chalcone-type polyphenol, via dehydration reaction of the hydroxyl groups of BCD and the benzoyl ring of Butein. Functional group changes in the conjugated BCD-Butein were comprehensively studied using UV-visible absorbance, Fourier transform-infrared, and X-ray photoelectron spectroscopic techniques. The electrochemical characteristics of BCD-Butein were explored using cyclic voltammetry, showing the reversible redox behavior (2e(-)/2H(+)) attributed to the catecholic OH group of Butein. The BCD-Butein-modified electrode exhibits a surface-confined redox process (R-2 = 0.99, I-pa and I-pc) at the interface, suitable for external mediatorless sensor studies. An enzymatic biomolecular sensor has been constructed using BCD-Butein-modified glassy carbon and a screen-printed electrode targeting sialic acid as the model clinical biomarker. With the enzyme sialic acid aldolase, BCD-Butein-modified substrate exhibited a selective conversion of sialic acid to N-acetyl-d-mannosamine and pyruvate, with a wide linear detection range (1-100 nM), the lowest detection limit of 0.2 nM, and a quantification limit of 0.69 nM, convenient for clinical threshold diagnosis.

Electrochemical energy conversion for hydrogen production is a crucial method to address the global energy demand. Here, a cost-effective approach for the preparation of a transition metal-based alloy electrode through electrodeposition with composition-modulated binary alloy electrodes is achieved using various electrolyte concentrations. An alloy electrode formed from the synergistic combination of Ni-Fe acted as a dual-path energy conversion anode in two different energy conversion systems, the oxygen evolution reaction (OER) and urea oxidation reaction (UOR). Under the optimal conditions, the Ni-5-Fe-3 alloy electrode consumes 1.48 V and 1.45 V vs. RHE for the OER and UOR, respectively. Evidential information from solar-powered water and urea oxidation with a low cell voltage (1.52 V) supports the feasibility of the prepared electrode materials. A lab scale direct oxidation of human urine has also been conducted and the obtained results are a promising cornerstone for waste-to-energy achievement.

Biosensors based on the electrochemical method offer unique advantages useful for portable application. Individual components of electrochemical biosensors comprise sensor element, bioreceptor molecules, bioaffinity layer/cross linking agents interfacing the sensor substrate, and bioreceptor and passivation layer. For disposable point-of-care diagnosis, cost-efficient carbon/paper-based screen-printed electrodes and lateral flow assays are largely explored. Unlike classical enzymes or antibodies, synthetic nucleic acids, biomimetics, and molecular imprinted polymers are the emerging modern bioreceptors for durable and cost-efficient commercial sensor application. This chapter introduces the basic concepts on safety aspects related to common in vitro diagnostics relating the WHO standards. It highlights the necessity of biocompatibility of sensor components against bioreceptors and the role of sensors in immune response correlating the infectious disease diagnosis and probing antibodies. Further, the role of the emerging internet of things, machine learning tools, and data science-related intervention that is desired in customization of advanced biosensor devices including clinical implementation study designs are also discussed.

Prostaglandin E2 (PGE2) is an important biomarker for cancers and chronic inflammation-associated diseases. While PGE2 plays a crucial role in the inflammatory response, chronically elevated PGE2 levels may contribute to disease onset and oxidative stress. Herein, hydroxypropyl beta-cyclodextrin (HPbCD)-functionalized MoO3 quantum dots (QDs) were synthesized with a hydrophilic exterior and hydrophobic core. The QDs were characterized for their physicochemical, bioimaging, and biocompatible nature. The QDs exhibited potential reactive oxygen species (ROS) scavenging and bioimaging in Caenorhabditis elegans. Further, the QD's high binding affinity-based nanomolar detection of PGE2 (2-40 nM) was performed at physiological pH. The detection mechanism was investigated using Stern-Volmer and Lineweaver-Burk equations, where K-q (8.9 x 10(15) and 2.85 x 10(14) L/mol/s) and K-b 1.1 x 10(7) M-1 with 1:1 binding interaction. The energetically favorable and spontaneous binding of PGE2 to MoCD QDs suggested strong host-guest inclusion-based detection of PGE2. The biosensor performance was tested with a potent interferent and validated in clinical serum samples. The developed biocompatible nanoquantum probe with triad applications, including oxidative stress management, bioimaging, and ultrasensitive detection of PGE2, is envisaged to be a valuable tool in molecular diagnosis in treatment of inflammation.

With the ever-growing global issues in health and environmental care, research on modern analytical devices is continuously progressing. A (bio)sensor is an analytical tool deployed in various sectors including clinical diagnosis, pharmaceuticals, and pollutant monitoring. According to World Health Organization, affordability, sensitivity, specificity, user-friendliness, rapidity and robustness, being equipment-free, and deliverability to users are desired for modern point-of-care diagnostics. In this aspect, enormous research development has been devoted in the area of biosensor field focused on electrode materials, customized bioreceptors, and target-specific detection applications. The cost-efficient and user-friendly integration of disposable electrodes holds huge potential for the global demand on point-of-care technology. The key R&D players involved in the manufacturing of disposable electrodes for customized (bio)sensor fabrication and its application demonstrated in active pharmaceuticals, biomolecules, and biomarker detection are discussed in this chapter. Emerging trends using a microfluidics-integrated sensor platform in modern biosensor research are also highlighted.

Electropolymerized materials are cost efficient, sensitive and durable for sensor applications. Herein, the cationic dye, methylene blue, electropolymerized on graphene oxide framework using cyclic voltammetry and processed for voltammetric sensor platform. The surface chemistry, topology and wettability of the prepared electrode material was comprehensively studied with Raman spectroscopy, field-emission scanning electron/atomic force microscopes and contact angle measurement. The electrochemical quartz crystal microbalance analysis was done to quantify the mass adsorbed on the graphene oxide framework. Cyclic voltammetric study of the prepared methylene blue-graphene oxide framework electrode exhibits a reversible redox behavior at the electrode -electrolyte interface, following surface confined process with a coefficient determination of 0.99. Electro-chemical sensing ability of the prepared electrode material was tested against the clinically important phyto-medicine, gallic acid. Linear sweep voltammetric analysis enabled that methylene blue-graphene oxide framework is highly sensitive and selective toward electrooxidation of gallic acid, exerting a detection limit of 49.2 mu M in the studied experimental concentration range from 50 mu M to 1 mM. Real sample validation with commercial herbal tablet extracts of Euphorbia prostrata containing spiked gallic acid suggest that the prepared sensor platform could be a potential analytical probe for herbaceutical testing.

Metal-free, cost-efficient, redox-active electrode materials, combining graphene derivatives with nitrogen-rich polymelamine (PM), are widely explored as an interface layer for electrocatalysis and an electrochemical sensor platform. However, conventional chemical routes often yield derivatives of PM suffering from impaired redox behavior, restricting their electron-transfer kinetics. Herein, an optimal potentiodynamic method has been established to electrodeposit PM on electrochemically reduced graphene oxide (ErGO). A supporting electrolyte, containing Cl-, enhances the formation of intermediates NH3+ and ═NH2+ at the monomeric melamine, eventually interacting with the residual oxygenated functional groups of ErGO to form PM. In situ Raman spectrum analysis revealed the influence of the defective area and the graphitization ratio on the ErGO surface during the course of electropolymerization of melamine. Under optimal electrodeposition conditions (E = 0-1.6 V; ν = 0.1 V/s), the amount of electrodeposited PM on the ErGO surface was determined to be 16.5 μg/(cycle·cm2), using electrochemical quartz crystal microbalance analysis. An ErGO-PM-modified glassy carbon electrode (GCE) and a screen-printed electrode exhibit the direct electrooxidation of acyclovir (ACV). Amperometric analyses of ErGO-PM-modified electrodes exhibited the lowest detection limit of 137.4 pM with analytical robustness, rapid steady state, and reproducibility promising for ACV detection in complex biological matrices.