Synergistic Signal Amplification-Initiated Innovative Self-Powered Photoelectrochemical Aptasensing: An Ingenious Photocathode Activated by the High-Light-Harvesting Photoanode

Abstract

Exploiting ingenious photoelectrodes and innovative signal amplification strategies has the potential to achieve high sensitivity in self-powered cathodic photoelectrochemical (PEC) analysis. In this work, a novel self-powered PEC sensing platform was constructed by integrating a synergistic signal amplification of an ingenious photocathode with a high light-harvesting photoanode. In the dual photoelectrode-based PEC system, the amplified photocurrent signals were induced by a synergistic enhancement:(1) the photocurrent of the BiOBr photocathode was improved by the incorporation of nitrogen-doped graphene; (2) the photocurrent of the self-powered sensor was activated by the high-lightharvesting Bi 2 S 3 −C 3 N 4 photoanode. Subsequently, the rational mechanism for synergistic signal amplification was investigated. For the construction of the sensing interface, an aptamer was introduced as the recognition element to specifically capture the streptomycin (STR) target. Under optimal conditions, the constructed self-powered aptasensor has the merits of good linear range (1 × 10 −11 to 5 × 10 −7 M), acceptable limit of detection (1.18 × 10 −12 M), and excellent stability and selectivity for STR detection. Additionally, the proposed self-powered aptasensor showed acceptable accuracy for the detection of STR in water. Hopefully, this might stimulate more interest in designing and constructing novel platforms for exquisite photocathodic monitoring of various contaminants in the environment.

Recent Trends in Self-Powered Photoelectrochemical Sensors: From the Perspective of Signal Output

“…The concentration of the target could be determined from the photocurrent by the self-powered sensor with excellent repeatability and high sensitivity. Additionally, our group proposed a self-powered PEC sensor was proposed based on a synergistic strategy (Figure C-b) . This dual-photoelectrode PEC system was based on the incorporation of nitrogen-doped graphene to enhance the photocurrent of the BiOBr photocathode by boosting the carrier density and accelerating the separation of electron–hole pairs.…”

“…Additionally, our group proposed a self-powered PEC sensor was proposed based on a synergistic strategy (Figure 2C-b). 42 This dualphotoelectrode PEC system was based on the incorporation of nitrogen-doped graphene to enhance the photocurrent of the BiOBr photocathode by boosting the carrier density and accelerating the separation of electron−hole pairs. A high-lightharvesting Bi 2 S 3 −C 3 N 4 photoanode was introduced to activate the photocurrent of the self-powered sensor and to improve the sensitivity of detection.…”

Photocathodic Activation of Peroxymonosulfate in a Photofuel Cell: A Synergetic Signal Amplification Strategy for a Self-Powered Photoelectrochemical Sensor

“…8 In the self-powered sensing process, the photoanode based on ntype semiconductors generates electrons with high mobility. 9 The electrons from the photoanode can combine with the holes from the photocathode via the external circuit, thus facilitating the spatial isolation of photocathodic electrons to analyte targets. 10 There is no doubt that the kernel component for the design of photofuel cells is to screen favorable photoactive materials as photoelectrodes.…”

Novel Porphyrinic Covalent Organic Polymer with Polarity-Switchable Dual Wavelength for Accurate and Sensitive Photoelectrochemical Sensing

“…The photoactive material serving as a light-to-electricity transducer is closely related to analytical performance. − Therein, porphyrinic covalent organic frameworks/polymers (PCOFs/PCOPs) possessing an extended π-conjugated structure have become an attractive candidate for material with ideal photoelectric conversion efficiency owing to its tunable function, excellent stability, and strong light absorption capacity. − So far, numerous PCOFs/PCOPs with high photoelectric conversion efficiency have been developed for PEC biosensing. − Admittedly, the photoactive material with a high photoelectric conversion efficiency has made a significant contribution to improving the PEC sensor sensitivity; however, it is also accompanied by some problems such as wide differences between photoelectrodes and greater susceptibility to interference factors. , And materials like this can only display a single-polarity photocurrent under light excitation, making insufficient accuracy and sensitivity in real sample detection. Therefore, we cast attention to the quest for a photoactive material with multiple characteristics in order to simultaneously give consideration to the sensitivity and accuracy of PEC biosensors.…”