Dye sensitized Ti3C2 MXene-based highly sensitive homogeneous photoelectrochemical sensing of phosphate through decomposition of methylene blue-encapsulated zeolitic imidazolate framework-90

Abstract

The previously reported homogeneous photoelectrochemical (PEC) sensor often suffers from the shortcomings of complicated dye-labeling procedure, poor photocurrent intensity, and weak stability. Exploiting novel homogeneous PEC sensors to circumvent above limitations is badly instant but faces a major challenge. This study presents a Ti3C2 MXene-based label-free homogeneous PEC sensor for highly sensitive analysis of phosphorus used methylene blue (MB) sensitized MXene@ITO photoelectrodes and functional zeolitic imidazolate framework-90 (ZIF-90). The MB sensitized MXene@ITO photoelectrodes exhibited excellent stability and elevation of photocurrent intensity. The MB was performed to encapsulate into ZIF-90 to form MB@ZIF-90 with one-step strategy. The prepared MB@ZIF-90 could be decomposed by target phosphorus due to the stronger coordination between phosphorus and Zn2+. As compared to the case where phosphorus was absent, a lot of MB was released and diffused to the MXene@ITO photoelectrode surface, and markedly increased PEC current was gained. Therefore, via these targets induced MB release mode and MB sensitized Ti3C2 MXene@ITO photoelectrodes, a high-performance homogeneous PEC phosphorus assay is realized, with a detection limit down to 0.21 μM. The phosphorus analysis with recovery ranged from 98.3% to 103.4% in environmental and biological samples, demonstrating the potential applicability of this PEC sensor.