Ultrasensitive detection strategy for CAP by molecularity imprinted SERS sensor based on multiple synergistic enhancement of SiO2@AuAg with MOFs@Au signal carrier

Abstract

Chloramphenicol (CAP) residue in food can cause great harm to human health, it is important to develop a rapid and sensitive method to detect CAP. Here, molecularly imprinted polymer (MIP) was combined with metal-organic frameworks@Au (MOFs@Au) collaborative construction surface-enhanced Raman spectroscopy (SERS) based aptasensor for CAP ultrasensitive detection. MOFs@Au first carried the Raman signal molecule toluidine blue (TB) and aptamer to form MOFs@Au@TB@Apt. In addition, rMIP (CAP was removed) was dropped onto the uniform three-dimensional (3D) SERS substrate SiO₂@AuAg to form SiO₂@AuAg@rMIP. In the presence of target CAP, it could be specifically captured with rMIP by covalent interaction and was recognised by the aptamer. During this time, SiO₂@AuAg@rMIP@CAP could selectively connect MOFs@Au@TB@Apt to realise synergistic enhance the Raman signal. Based on this principle, the proposed SERS aptasensor exhibits excellent sensitivity with a detection limit of 7.59×10^-13 M for CAP, providing a new strategy for trace detection in food.

Keywords: Chloramphenicol; Metal-organic frameworks@Au; Molecularly imprinted polymer; SERS biosensor.