Recent advances of functional nanomaterials for screen-printed photoelectrochemical biosensors

Abstract

Photoelectrochemical (PEC) biosensors have attracted intensive attention due to their advantages, including low background, high sensitivity, high specificity and rapid response. In recent years, the introduction of disposable screen-printed electrodes (SPE) has greatly facilitated the development of PEC biosensors, making screen-printed PEC biosensors a promising analytical tool for various applications. Photoactive nanomaterials play a crucial role in the construction of screen-printed PEC biosensors as they can be used not only as photoelectric conversion platforms but also as loading platforms for recognition elements. However, pure photoactive materials usually suffer from some drawbacks, such as inherent toxicity, wide bandgap, and high electron-hole pair recombination rate. Therefore, it is necessary to improve the photoelectric properties of these materials through various design strategies. Moreover, to obtain highly sensitive screen-printed PEC biosensors, it is usually necessary to combine the high-performance photoelectrodes with various signal amplification strategies. In view of this, we provide the first systematic summary of photoactive materials for screen-printed PEC biosensors in this paper, classifying them into four main categories: metal oxides, metal chalcogenides, carbon nanomaterials and bismuth-based nanomaterials. Meanwhile, we focus on the design strategies for photoactive materials, including morphology modulation, elemental doping, and heterostructure construction. In addition, we introduce signal amplification strategies, such as the enzyme label amplification (ELA) strategy, polymerase chain reaction (PCR) strategy, rolling circle amplification (RCA) strategy, and hybridization chain reaction (HCR) strategy, through representative screen-printed PEC immunosensors and screen-printed PEC aptasensors. Finally, we discuss the current challenges and prospects of screen-printed PEC biosensors. We hope to provide readers with a comprehensive understanding of the recent advances in screen-printed PEC biosensors and provide a feasible guidance for the future development of this field.