Sensitive detection of microRNAs (miRNAs) holds significant importance for the early diagnosis of cancer. Since current sensitive nucleic acid detection methods like recombinase polymerase amplification-clustered regularly interspaced short palindromic repeats (RPA-CRISPR)/Cas12a are not suitable for detecting short-stranded miRNAs, we introduced a T4 ligase-based ligation process to the RPA-CRISPR/Cas12a system and developed a novel miRNA detection method termed ligation-RPA-CRISPR/Cas12a (LRCC). This assay utilizes a glycerol-enhanced one-pot reaction strategy combined with a lateral flow assay (LFA) to streamline the operation, minimize aerosol contamination, and improve point-of-care testing performance. Kinetic studies have shown that the catalytic efficiency of the glycerol-enhanced one-pot reaction is 3.11 and 2.09 times higher than that of the direct one-pot and stepwise methods, respectively. By synthesizing "three-in-one" Au-Pt nanostars (Au@Pt NSs) as probes and stabilizing them via "click" chemistry modification, this work enabled a trimode detection approach (colorimetric, photothermal, and surface-enhanced Raman spectroscopy (SERS)) with improved accuracy. In the experiment, tetrahedron DNAs were immobilized on the test line of the strip to enhance the capture efficiency of probes, thereby improving the detection sensitivity. The entire detection process was completed in 70 min with detection limits of 23.6 fM for colorimetric (C-LFA), 2.19 fM for photothermal (P-LFA), and 72.29 aM for SERS (S-LFA). The results demonstrate the strong practical applicability of the LRCC strategy, which plays a crucial role in miRNA-based early disease diagnosis.

The portable detection of AFB1 is of great significance in the field of food safety. In this work, an aggregation-induced emission (AIE) metal-organic framework (MOF) material ZMA was synthesized. After in situ reduction of Pt and conjugation with DNA, a multifunctional nanoprobe ZMA@Pt-Probe was obtained. On the other hand, using the competitive recognition of aptamers, combined with the nucleic acid amplification of the rolling circle amplification (RCA) and CRISPR/Cas12a systems, alkaline phosphatase (ALP) was released through trans-cleavage. Subsequently, ALP hydrolysis, ascorbic acid reduction of Cu(II), and Cu(I) click reaction yielded Trigger DNA, which bound ZMA@Pt-Probe on the test line, achieving triple-mode signal-on detection (colorimetric, fluorescent, enhanced colorimetric). The detection limits of the three modes are 12.73, 7.332 and 5.839 pg/mL, respectively. This triple-mode sensing strategy not only offers mutual validation to ensure high accuracy but also exhibits excellent sensitivity and portability, holding great promise for on-site food safety monitoring of AFB1 in complex matrices.

This study employed a reverse engineering approach to evaluate and estimate the key excipients in the Reference Listed Drug (RLD), thereby supporting the development of cost-effective generic pharmaceutical products. By combining liquid chromatography-quadrupole-time-of-flight mass spectrometry (LC-Q-TOF-MS) with high-performance liquid chromatography-evaporative light scattering detection (HPLC-ELSD), qualitative and quantitative analyses of tyloxapol in a formulation were achieved. MS showed that the tyloxapol reference standard, tobramycin eye drops, and the excipient tyloxapol sample 03 exhibited essentially consistent retention times, charge states, m/z ratios, and molecular weight distributions. The spectral characteristics of excipient tyloxapol sample 01 and excipient tyloxapol sample 02 were essentially consistent, as reflected in their retention times and three sets of mutually matched characteristic MS peaks. Based on these qualitative results, a quantitative HPLC-ELSD method using a TSKgel G2000SWXL column was established for the content analysis of tyloxapol. Methodology validation demonstrated that the method exhibited a strong linear relationship within the concentration range of 243.9-731.7 µg mL-1 (R2 = 0.999), with favorable accuracy (recovery rate = 99-106%), precision (repeatability RSD ≤ 2.2%, intermediate precision RSD ≤ 1.6%), specificity, and solution stability. The combination of Q-TOF MS and HPLC-ELSD can be applied for the qualitative and quantitative analysis of excipients in pharmaceutical formulations, supporting the reverse engineering process in generic drug development.

Enhanced ochratoxin A (OTA) monitoring is vital for ensuring food safety and mitigating public health risks. Here, we developed a dual-mode photoelectrochemical (PEC)-electrochromic (EC) sensor on a single ITO electrode for OTA detection, offering simplified fabrication and enhanced portability. To improve sensitivity, a Ni-ZnIn2S4/CdSe Z-scheme heterojunction was employed as the substrate material, dramatically enhancing the initial photocurrent in this signal-off sensor. Furthermore, we employed an aptamer that forms an antiparallel Gquadruplex structure upon binding to OTA, which then interacted with hemin to function as a DNAzyme. The resulting DNAzyme could catalyze the bio-precipitation (BCP) reaction, amplifying both PEC and EC signal changes. The achieved detection limits were 0.28 pg mL-1 (PEC) and 0.39 pg mL-1 (EC), respectively. This study also systematically investigated how metal doping and heterojunction formation enhance photoelectric response. Furthermore, extending the G-rich sequences in the aptamer enables detection of diverse targets, significantly broadening the method's applicability.

A dual-mode split-type aptasensor was constructed based on a dual-signal source locking and Fe surface doping strategy. The dual signal sources were locked with each other through the reaction of Fe3 + (acting as the PEC signal source) with 2-aminoterephthalic acid (ATA, serving as the fluorescent signal source), forming the metal-organic framework MIL-53. Unlike conventional strategies that directly utilize iron-doped semiconductors as the photoelectric substrate, here we harness Fe2+ ions released after target recognition to enhance the photo-electrochemical signal. This work employs ZnIn2S4 (ZIS) as the photoelectric substrate material and MIL-53 modified with phenylboronic acid (PBA) as a probe. A sandwich-type structure is formed through the recognition of carcinoembryonic antigen (CEA) by aptamers and PBA. The MOF material is degraded using a disintegrator (containing ZrCl4, Na3C6H5O7 & sdot;2 H2O, and ascorbic acid AA) to release Fe2+ and ATA. The released Fe2+ ions undergo surface doping into ZIS, which changes its semiconductor properties by increasing the open-circuit voltage as well as establishing localized electric fields (LEF) to enhance the separation/migration of photo-generated carriers and catalyze the oxidation of the electron donor ascorbic acid (AA). Such synergistic mechanism amplifies the PEC response and enhances the detection sensitivity of PEC mode. Concurrently, the released ATA demonstrated strong fluorescence emission, enabling ultrasensitive fluorescence detection. The fluorescence emission mechanisms under different pH conditions were investigated detaily. The developed dual "signal-on" sensor is characterized by its simplicity, rapidity, and ease of implementation.

A self-powered dual-electrode aptasensor was developed for the detection of tumor marker carcinoembryonic antigen (CEA). The composite BiVO4/ZnIn2S4, which is capable of forming a Z-scheme heterojunction, was chosen as the photoanode, and the AuNP/CuBi2O4 complex was chosen as the photocathode in photoelectrochemical (PEC) detection. The experiments showed that the constructed self-powered dual-electrode system had a good photoelectric response to white light, and the photocurrent signal of the photocathode was significantly enhanced under the influence of the photoanode. The introduction of G-quadruplex/hemin DNAzyme through aptamer recognition resulted in the generation of insoluble species through catalytic reaction, which led to a significant decrease in the photocurrent, and achieved a highly sensitive detection of the target CEA with a detection limit of 0.021 pg/mL. At the same time, the developed photocathode detection exhibited good selectivity and could effectively avoid interference, making it suitable for real sample analysis. It is expected that this study can facilitate the application of PEC sensors in point-of-care (POC) diagnosis for life analysis. Self-powered dual-photoelectrode photoelectrochemical aptasensor amplified by hemin/ G-quadruplex-based DNAzyme

Stimuli-responsive magnetic mesoporous silica microspheres Fe3O4@mSiO2 have been widely used in biosensors. Here, we developed a CRISPR/Cas 12a system triggered Fe3O4@mSiO2 for label-free detection of cancer marker miRNA-21. A lot of methylene blue (MB) molecules, as surface-enhanced Raman scattering (SERS) signal molecules, were loaded into the mesopores of Fe3O4@mSiO2. G-quadruplex/hemin complexes, as gates, were capped on the surface of Fe3O4@mSiO2. Target miRNA-21 initiated primer exchange reaction (PER), whose product could activate the CRISPR/Cas 12a system. Thus, the activated Cas12a non-specifically cleaved the singlestranded DNA linked between G-quadruplex and Fe3O4@mSiO2, resulting in the removal of the cap and the release of the MB. The supernatant was dropped on the surface of ZnO NRs@AuNPs, and MB was detected through SERS to realize the sensitive detection of target miRNA-21. Meanwhile, the released G4/hemin complex in the supernatant was used to catalyze the oxidation of 2,2 '-azinobis (3-ethylbenzothiazoline-6-sulfonic acid ammonium salt) (ABTS) for colorimetric detection. The limits of detections were 4.7 aM and 0.18 fM for SERS and colorimetry, respectively. In this way, a label-free SERS-colorimetry dual-mode sensing platform was established for highly sensitive analysis of oligonucleotides

Early diagnosis of breast cancer is crucial for enhancing patient survival rates. This study developed a portable electrochemical sensor for simultaneous detection of carcinoembryonic antigen (CEA) and cancer antigen 15-3 (CA15-3). Glutaraldehyde cross-linked denatured bovine serum albumin and polydopamine (PDA) was used as an anti-fouling electrochemical sensor interface for screen-printed electrode (SPE). Etched UiO-66-d was employed to adsorb methylene blue and neutral red dyes, followed by modification with phenylboronic acid (PBA) to produce two redox tags. Aptamer DNA and PBA were used to recognize target CEA and CA15-3 to form sandwich structures. To enhance the Point-of-Care Testing (POCT) performance, a portable dual-channel electrochemical detection device was developed integrated with dual-channel SPE for simultaneous detection of CEA and CA15-3. The detection limits for CEA and CA15-3 were determined to be 0.35 pg/mL and 0.0032 U/mL, respectively. From analyzing both serum and nipple discharge samples, it indicates that using nipple discharge as the detection object can effectively differentiate atypical ductal hyperplasia (a pre-breast cancer lesion) from benign hyperplasia, which holds significant implications for early breast cancer diagnosis.

A lateral flow assay (LFA) was developed for the simultaneous or separate detection of mercury ion and silver ion based on isothermal nucleic acid amplification. T-Hg2+-T and C–Ag+-C were utilized in the isothermal nucleic acid amplification strategy to form specific complementary base pairs. Under the action of KF polymerase and endonuclease Nt.BbvCl, trace amounts of Hg2+ and Ag+ were converted to Product-Hg2+ and Product-Ag+ as bridges. Biotin-labeled capture strands (Biotin-DNA1, Biotin-DNA1, and Biotin-DNA3) immobilized on the test strips could capture the Au NPs-DNA nanoprobes by hybridization with the generated bridge products for monitoring of two heavy metal ions simultaneously or separately. The assembly method of DNAs on the nanoprobes was explored, and the DNA sequences on the nanoprobes were designed so that only one kind of DNA strand was used to bind to all three capture DNA strands on the C, T1, and T2 bands. Under optimal detection conditions, the limits of detection for Hg2+ and Ag+ were 2.19 and 5.41 pM, respectively, with desired selectivity and reproducibility.

A CRISPR-Cas12a controlled chemiluminescence resonance energy transfer (CRET) biosensor was constructed for the detection of cancer biomarker carcinoembryonic antigen (CEA). The CRET probe, a single-strand DNA (ssDNA) with hemin/G-quadruplex on one end and CdSe/ZnS quantum dots (QDs) nanosphere on the other end, was used as the substrate for the trans-cleavage of CRISPR/Cas12a system. The hemin/G-quadruplexes catalyzed the oxidation of luminol in the presence of H2O2. The generating chemiluminescence could excite the CdSe/ZnS QDs encapsulated in the nanosphere, producing CRET. When target CEA specifically identified dual aptamers on the surface of magnetic beads (MBs), the terminal sequence of Aptamer 2 triggered the hybridization chain reaction (HCR), whose product initiated the trans-cleavage activity of CRISPR/Cas12a and destroyed the CRET system. As a result, the luminescence of QDs nanosphere was declined. With HCR, CRISPR-Cas12a trans-cleavage, and mimic DNAzyme catalytic amplification, the biosensor gave a detection limit down to 5.6 pg/mL. Due to the application of CRISPR/Cas12a, the CRET sensor with the characteristics of easy operation and no external light source required was more suitable for point-of-care testing (POCT) detection of various targets.

In recent years, electrochemical sensors for nucleic acid testing based on CRISPR/Cas12a technology have attracted widespread interest due to their ease of operation and high detection sensitivity. Here, a label-free electrochemical sensor amplified by primer exchange reaction (PER), hybridization chain reaction (HCR) and CRISPR/Cas12a system was developed for analyzing miRNA- 155 and PCB 77. In the presence of targets, PER was initiated, whose products could be used to trigger the trans-cleavage activity of Cas12a for the single-stranded DNA (ssDNA) on the electrode. Afterwards, with the amplification of HCR on the electrode and electrostatic adsorption of Ru(NH3)63+, the concentration of the targets could be indicated by the DPV intensity with a low background signal. The detection limits for miRNA- 155 and PCB 77 were estimated to be 67 aM and 6.9pg/L, respectively. This work provides a versatile method for sensitive detection of different targets using the same crRNA and can be used in various biochemical investigations.

An electrochemical sensor assisted by primer exchange reaction (PER) and CRISPR/Cas9 system (PER-CRISPR/Cas9-E) was established for the sensitive detection of dual microRNAs (miRNAs). Two PER hairpin (HP) were designed to produce a lot of extended PER products, which could hybridize with two kinds of hairpin probes modified on the electrode and initiate the cleavage of two CRISPR/Cas9 systems guided by single guide RNAs (sgRNAs) with different recognition sequences. The decrease of the two electrochemical redox signals indicated the presence of dual-target miRNAs. With the robustness and high specificity of PER amplification and CRISPR/Cas9 cleavage system, simultaneous detection of two targets was achieved and the detection limits for miRNA-21 and miRNA-155 were 0.43 fM and 0.12 fM, respectively. The developed biosensor has the advantages of low cost, easy operation, and in-situ detection, providing a promising platform for point-of-care detection of multiple miRNAs.

This work develops a novel photoelectrochemical sensor for the detection of carcinoembryonic antigen (CEA) based on the composite of UCNPs with semiconductors and conformational changes in the DNA structure. Firstly, SnS2, ZnIn2S4 and UCNPs were assembled on the surface of the ITO electrode. Then Au NPs were dropped, which could facilitate the coupling of CdSe NPs modified DNA1 via Au-S bond, giving an ITO/SnS2/ZnIn2S4/UCNPs/ CdSe heterojunction structure. When irradiated with 980 nm near-infrared (NIR) light, the UV-visible light emitted by the UCNPs could excite the nanocomposite, producing an enhanced photoelectric reaction. Subsequently, CEA aptamer and DNA2-modified SiO2 were added to form a Y-shaped DNA structure. At this time, the photocurrent was significantly reduced by the combination of the light-blocking effect of SiO2 and the departure of CdSe NPs from the electrode surface. When the target CEA was added, the recognition between CEA and the aptamer led to the collapse of the Y-shaped DNA structure, the restoration of hairpin DNA and the proximity of CdSe to the electrode. Accordingly, the photocurrent signals enhanced again. Under optimal experimental conditions, the detection limit as low as 0.3 pg mL-1 was obtained with good selectivity, achieving a sensitive "on-off-on" photoelectrochemical sensor for CEA detection.

The self‐assembled hole transporting molecules (SAHTMs) bearing anchoring groups have been established as the hole transporting layers (HTLs) for highly efficient p–i–n perovskite solar cells (PSCs), yet their stability and engineering at the molecular level remain challenging. A topological design of highly anisotropic aligned SAHTM‐based HTLs for operationally stable PSCs that exhibit exceptional solar‐to‐electric power conversion efficiencies (PCEs) is demonstrated. The judiciously designed multifunctional self‐assembled molecules comprise the donor–acceptor subunit for hole transporting and the phosphonic acid group for anchoring, realizing face‐on π‐stacking parallel to the transparent conductive oxide substrate. The high affinity of SAHTMs to the multi‐crystalline perovskite thin film benefits passivating the perovskite buried interface, strengthening interfacial contact while facilitating interfacial hole transfer. Consequently, highly efficient p–i–n PSC devices are obtained with a champion PCE of 23.24% and outstanding operational stability toward various environmental factors including long‐term full sunlight soaking at evaluated temperatures. Perovskite solar modules with a champion efficiency approaching 20% are also fabricated for an active device area above 17 cm 2 .

Herein, a chemiluminescence (CL) biosensor based on CRISPR-Cas12a and cation exchange reaction was constructed to detect the biomarker microRNA-21 (miRNA-21). The rolling circle amplification (RCA) reaction was introduced to convert each target RNA strand into a long single-stranded DNA with repeated sequences, which acted as triggers to initiate the transcleavage activity of CRISPR-Cas12a. The activated Cas12a could cleave the biotinylated linker DNA of CuS nanoparticles (NPs) to inhibit the binding of CuS NPs to streptavidin immobilized on the surface of the microplate, which strongly reduced the generation of Cu2+ from a cation exchange between CuS NPs and AgNO3, and thus efficiently suppressed the CL of Cu2+-luminol-H2O2 system, giving a “signal off” biosensor. With the multiple amplification, the detection limit of the developed sensor for miRNA-21 reached 16 aM. In addition, this biosensor is not only suitable for a professional chemiluminescence instrument but also for a smartphone used as a detection tool for the purpose of portable and low-cost assay. This method could be used to specifically detect quite a low level of miRNA-21 in human serum samples and various cancer cells, indicating its potential in ultrasensitive molecular diagnostics.

Coronavirus pandemic has been a huge jeopardy to human health in various systems since it outbroke, early detection and prevention of further escalation has become a priority. The current popular approach is to collect samples using the nasopharyngeal swab method and then test for RNA using the real-time polymerase chain reaction, which suffers from false-positive results and a longer diagnostic time scale. Alternatively, various optical techniques, namely, optical sensing, spectroscopy, and imaging shows a great promise in virus detection. In this mini review, we briefly summarize the development progress of vibrational spectroscopy techniques and its applications in the detection of SARS-CoV family. Vibrational spectroscopy techniques such as Raman spectroscopy and infrared spectroscopy received increasing appreciation in bio-analysis for their speediness, accuracy and cost-effectiveness in detection of SARS-CoV. Further, an account of emerging photonics technologies of SARS-CoV-2 detection and future possibilities is also explained. The progress in the field of vibrational spectroscopy techniques for virus detection unambiguously show a great promise in the development of rapid photonics-based devices for COVID-19 detection.

Perovskite nanocrystals (PNCs) have recently become promising optoelectronic materials due to their excellent photophysical properties. However, the highly dynamic binding state between ligands and the surface of PNCs has severely restricted their luminescent properties and stabilities. In this work, 1,3-bisbenzyl-2-oxoimidazolidine-4,5-dicarboxylic acid (cycle acid, CA) is introduced as both an etchant and a ligand upon post-synthetic surface treatment of PNCs. By removing the imperfect octahedrons [PbX6]4-and passivating the surface defects synergistically, this treatment improves photoluminescence quantum yields from 76% to 95% and enhances the stability of PNCs against polar solvent, moisture, heat, and illumination. Meanwhile, CA can effectively and instantly recover the luminescence emission for aged PNCs. As a result, the CA-CsPbBr3 PNCs and CA-CsPbIxBr3_x PNCs are applied as color-converting lay-ers on a blue LED chip for warm white light-emitting diodes (WLEDs) with a color coordinate of (0.41, 0.40). Importantly, the CA-based WLED device exhibits superior stability in operational conditions. (c) 2022 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Despite the great promise of cancer theranostic platforms, accurate diagnosis and effective treatment are still highly challenging. In this work, nanodevice for intracellular miRNAs detection and artificially controlled drug releasement was developed based on upconverting nanoparticles (UCNPs). For analysis aspect, DNAzymes amplified miRNA-21 detection was carried out, giving excellent sensitivity with detection limits of 1.8 × 10-11 M. Moreover, intracellular fluorescence imaging permitted in situ diagnoses of miRNA-21 expression in living cells. Once the test identifies tumor markers, treatment can be performed. Here, artificially controlled chemo-gene synergetic therapy nanodevice was obtained by integrating UCNPs with photocleavable linkers (PC-linkers). In vitro and in vivo experiments verified the potential application of prepared nanodevice in cancer theranostics.