Self-powered photoelectrochemical sensing for sensitive detection of chloramphenicol based on sulfur-vacancy engineered MoS2 nanoribbons/plasmonic Ti3C2 MXene with continual injection of photoinduced electrons

Accurate detection of antibiotic concentration in a matrix is vital for determining the contamination status. In this study, we have developed an ultrasensitive self-powered photoelectrochemical (PEC) sensor based on MoS2/Ti3C2 heterojunction, where sulfur vacancy engineered MoS2 nanoribbons were first grown in situ onto the plasmonic Ti3C2 MXene via a facile thermal treatment method. With the introduction of nonmetallic plasmonic Ti3C2, the constructed MoS2/Ti3C2 heterostructure facilitated the continuous photoelectron injection from MoS2 to Ti3C2 MXene, resulting in stable surface plasmon resonance (SPR) effect and enhanced photoelectric conversion. Compared to MoS2 alone, the PEC response of as-prepared MoS2/Ti3C2 heterojunction was increased by five times. Due to the excellent PEC properties of the MoS2/Ti3C2 heterostructure, a new ultrasensitive PEC aptasensor was fabricated with the assistance of chloramphenicol (CAP) aptamer. The developed aptasensor displayed satisfactory stability over a period of 11 days and high selectivity, a wide linear response range (0.1 nM to 0.01 mM) and a low detection limit (0.034 nM). Therefore, it can be successfully applied to CAP detection in environmental samples. This work provided a signal amplification strategy to fabricate efficient self-powered PEC sensing platforms.