A molecularly imprinted photoelectrochemical sensor based on oxygen-vacancy-modified TiO2 nanotube arrays for the highly specific detection of tetracycline hydrochloride

A novel molecularly imprinted photoelectrochemical sensor based on CdS QDs /Ov-TNTs was fabricated. • CdS QDs and Ov-TNTs cooperatively achieved the spatial separation of electron-hole pairs. • The sensor offered a wide linear range from 0.1 to 100 ng mL −1 and a low detection limit of 0.03 ng mL −1 . The excessive use of tetracycline hydrochloride (TCH) poses a threat to ecological integrity and public health. This urgency necessitates the development of sensitive, accurate, and rapid sensing technologies for TCH detection. Herein, we developed a novel molecularly imprinted photoelectrochemical sensor based on CdS and oxygen vacancy-regulated TiO 2 nanotube arrays (Ov-TNTs). The introduction of oxygen vacancies broadens the light absorption range of TiO 2 and facilitates the effective separation of photogenerated electron-hole pairs. Additionally, the decoration with narrow-bandgap CdS QDs (2.4 eV) further enhances the visible-light harvesting capability of the sensor. Furthermore, a molecularly imprinted polymer (MIP) film with specific recognition capability, which offers the advantages of facile preparation, time efficiency, and low cost, was introduced onto the sensing platform to further optimize its performance and significantly enhance the sensor's selectivity and anti-interference ability. The proposed sensor exhibited excellent analytical performance for TCH detection, offering a wide linear range from 0.1 nM to 0.1 μM and a low detection limit of 0.032 nM (S/N = 3). This strategy provides a universal platform for detecting other antibiotics through the replacement of molecularly imprinted films in aquatic environments. Download: Download high-res image (111KB) Download: Download full-size image