Ultra-sensitive electrochemical detection of ampicillin with hollow tubular mesoporous In2O3@Au@Apta nanofibers as electrode materials

A mesoporous In 2 O 3 @Au nanofiber was proposed for the electrochemical aptasensor for the detection of ampicillin (AMP). In this sensor, Au-modified In 2 O 3 (In 2 O 3 @Au) was incubated with an aptamer (Apta), and the resulting electrode modification was integrated on the surface of the working electrode. Cyclic Voltammetry (CV), Differential Pulse Voltammetry (DPV) and Electrochemical Impedance Spectroscopy (EIS) were used to realize the research of electrode modification and the detection of AMP. According to the detection results of DPV, the current value and the logarithm of the concentration showed an ideal linear relationship. R 2 reached as high as 0.9871, and the detection limit was 1 pg/mL. It has good selectivity and cycle stability. Compared with other antibiotics or amino acids, it has higher selectivity for AMP. The proposed In 2 O 3 @Au@Apta can effectively and sensitively detect AMP in milk and has broad application prospects. • The hollow tubular mesoporous In 2 O 3 @Au nanofibers were synthesized by electrospinning. • PVP with different molecular weights formed a tubular mesoporous structure, which enhanced the electrochemical performance. • The aptamer sensor can efficiently and sensitively detect ampicillin from milk samples.