Band Alignment Modulated Polarity-Switchable PEC Ratiometric Sensor through Coupling a pH-Responsive CuTCPP MOF with i-Motif Sensing tool.
Xuechen ZhangYanru ZhangXue FanWenbo SongPublished in: ACS sensors (2024)
In conventional ratiometric photoelectrochemical (PEC) sensors, the detection and reference signals are output sequentially from two independent photosensitive materials. In such a "two-to-two" ratiometric mode, unavoidable difference during dual-interface modification exists, resulting in questionable ratiometric signals and detection results. To address this issue, we propose a novel "one-to-two" ratiometric PEC sensor on a single electrode interface through pH-modulated band alignment engineering. The double ratiometric signals are generated by the synergistic action of a pH-responsive CuTCPP/WS 2 photoelectric substrate material and the i-motif sensing tool. Specifically, a ternary heterostructure to generate a photoanodic detection signal is formed under alkaline conditions between CuTCPP/WS 2 and signal label CdS QDs binding to the i-motif. While under acidic conditions, a photocurrent polarity conversion and signaling labels detachment, induced by the band realignment of CuTCPP/WS 2 and the i-motif conformational switching, produce a reliable internal reference photocathodic signal. The feasibility of this two-wing signal generation strategy is validated by detecting mycotoxin ochratoxin A, which achieves accurate and reliable ratio detection results. Overall, this work provides guidance for the design of a PEC ratiometric determination system and exhibits great potential to be applied in practical analysis research.
Keyphrases
- quantum dots
- fluorescent probe
- sensitive detection
- living cells
- loop mediated isothermal amplification
- label free
- hydrogen peroxide
- energy transfer
- real time pcr
- drug delivery
- molecular dynamics
- mass spectrometry
- gold nanoparticles
- high resolution
- visible light
- nitric oxide
- risk assessment
- liquid chromatography
- climate change
- low cost
- molecularly imprinted