This work presented a point-of-care (POC) photoelectrochemical (PEC) biosensing for the detection of human papillomavirus-16 (HPV-16) on a portable electrochemical detection system by using CRISPR-Cas12a trans-cleaving the G-quadruplex for the biorecognition/amplification and a hollow In2O3–In2S3-modified screen-printed electrode (In2O3–In2S3/SPE) as the photoactive material. G-quadruplexes were capable of biocatalytic precipitation (H2O2-mediated 4-chloro-1-naphthol oxidation) on the In2O3–In2S3/SPE surface, resulting in a weakened photocurrent, but suffered from trans-cleavage when the CRISPR-Cas12a system specifically recognized the analyte. The photocurrent results could be directly observed with the card-sized electrochemical device via a smartphone, which displayed a high-value photocurrent for these positive samples, while a low-value photocurrent for the target-free samples. Such a system exhibited satisfying photocurrent responses toward HPV-16 within a wide working range from 5.0 to 5000 pM and allowed for detection of HPV-16 at a concentration as low as 1.2 pM. The proposed assay provided a smartphone signal readout to enable the rapid screening PEC determination of HPV-16 concentration without sophisticated instruments, thus meeting the requirements of remote areas and resource-limited settings. We envision that combining an efficient biometric PEC sensing platform with a wireless card-sized electrochemical device will enable high-throughput POC diagnostic analysis.

Point-of-care testing (POCT) technology has made major breakthroughs in community medicine and physician office situations, in tandem with the more ubiquitous and intensive usage of highly integrated quick detection equipment for illness diagnosis, personal care, and mobile healthcare. Although the photoelectrochemical (PEC)-based POCT platform offers the benefits of cheap cost and good user engagement, its commercialization is still limited by the photodetection components’ downsizing and mobility, among other factors. In this work, a novel highly integrated PEC biosensor aided by piezophototronics to enhance the efficiency of PEC testing was reported for flexible detection of cancer-associated antigens in biological fluids (prostate-specific antigen, PSA, used as an example). Multiple signal enhancement strategies, including a magnetic bead-linked enzyme-linked immune system catalyzing the production of ascorbic acid from the substrate and a piezoelectric-assisted enhancement strategy, were used for sensitive detection of the analyte to be tested in human body fluids. Unlike the electron transfer mechanism in heterojunctions, piezoelectric semiconductors promote the transfer of electrons and holes by generating piezoelectric potentials in the ultrasonic field, thus contributing to the performance of the PEC testbed. Under optimized conditions, the test platform achieves good correspondence for PSA at 0.02–40 ng mL–1. Impressively, the test devices are comparable to or even superior to gold standard ELISA kits in terms of cost approval and batch testing. This research demonstrates the potential of piezoelectric semiconductors for POC applications in revolutionary PECs and offers innovative thoughts for the development of new PEC bioanalytical components.

Early diagnosis of cancers relies on the sensitive detection of specific biomarkers, but most of the current testing methods are inaccessible to home healthcare due to cumbersome steps, prolonged testing time, and utilization of toxic and hazardous substances. Herein, we developed a portable selfpowered photoelectrochemical (PEC) sensing platform for rapid detection of prostate-specific antigen (PSA, as a model diseaserelated protein) by integrating a self-powered photoelectric signal output system catalyzed with chemiluminescence-functionalized Au nanoparticles (AuNPs) and a phosphomolybdic acid (PMA)based photochromic visualization platform. TiO 2 -g-C 3 N 4 -PMA photosensitive materials were first synthesized and functionalized on a sensor chip. The sensor consisted of filter paper modified with a photocatalytic material and a regional laser-etched FTO electrode as an alternative to a conventional PEC sensor with a glass-based electrode. The targeting system involved a monoclonal anti-PSA capture antibody-functionalized Fe 3 O 4 magnetic bead (mAb 1 -MB) and a polyclonal anti-PSA antibody (pAb 2 )-N-(4aminobutyl)-N-ethylisoluminol-AuNP (ABEI-AuNP). Based on the signal intensity of the chemiluminescent system, the photochromic device color changed from light yellow to heteropoly blue through the PMA photoelectric materials integrated into the electrode for visualization of the signal output. In addition, the electrical signal in the PEC system was amplified by a sandwich-type capacitor and readout on a handheld digital multimeter. Under optimum conditions, the sensor exhibited high sensitivity relative to PSA in the range of 0.01−50 ng mL −1 with a low detection limit of 6.25 pg mL −1 . The flow-through chemiluminescence reactor with a semiautomatic injection device and magnetic separation was avoid of unstable light source intensity inherent in the chemiluminescence process. Therefore, our strategy provides a new horizon for point-of-care analysis and rapid cost-effective clinical diagnosis.

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