Amorphous/Crystal Heterostructure Coupled Oxygen Vacancies-Sensitized TiO2 with Conspicuous Charge-Transfer Resonance for Efficient Sers Detection of Chloramphenicol

Antibiotic environmental pollutants, such as chloramphenicol (CAP), have attracted global attention. They usually show a complex background, low concentration, and weak chemical activity in water bodies, making their rapid and on-site detection a scientific challenge. Surface-enhanced Raman spectroscopy (SERS) technology can facilitate the practical application of CAP detection; however, it is important to match substrate materials with excellent SERS properties. The most challenging aspect of SERS substrate design is the realization of energy level matching and charge-transfer resonance. Herein, a crystal-amorphous TiO2 substrate material rich in oxygen vacancies, CA-V-TiO2, is proposed. Through the cooperative regulation of vacancies and amorphous state, the bandgap structure can be optimized, the charge-transfer efficiency can be improved, and finally the energy level matching between CA-V-TiO2 substrate and molecules can be realized and the conspicuous charge-transfer resonance phenomenon can be generated, effectively optimizing the performance of SERS substrate. In addition, CA-V-TiO2 substrate is used for sensitive detection of CAP, showing multiple advantages such as low detection limit, good reproducibility, and high stability, which can realize trace CAP detection in actual water environments. This work provides a reliable platform for SERS on-site detection of CAP in the field of food and environmental monitoring.

Automated summary

This study proposes a new substrate material, CA-V-TiO2, which achieves energy level matching and charge-transfer resonance through the regulation of vacancies and amorphous state, optimizing the performance of SERS substrate. The CA-V-TiO2 substrate enables sensitive detection of chloramphenicol with low detection limit, good reproducibility, and high stability.