Electrochemical surface plasmon resonance (EC-SPR) aptasensor for ampicillin detection

Area of Science:

• Analytical Chemistry
• Biochemistry
• Biosensing Technology

Background:

• Surface plasmon resonance (SPR) is a sensitive label-free technique for studying surface-based molecular interactions.
• Hybrid methods combining electrochemistry and optical techniques offer enhanced monitoring of biochemical processes.
• Ampicillin, a widely used antibiotic, poses risks due to residues in food and the environment, necessitating reliable detection methods.

Purpose of the Study:

• To develop and characterize an electrochemical aptasensing platform for ampicillin detection using SPR.
• To establish an efficient method for functionalizing a gold chip for specific ampicillin capture.
• To evaluate the performance of the developed SPR biosensor for ampicillin quantification and selectivity.

Main Methods:

• Functionalization of a gold chip using potential-assisted immobilization with thiol-terminated aptamers and mercaptohexanol.
• Electrochemical characterization of the aptasensing platform using multipulse amperometry.
• Real-time monitoring of ampicillin binding via surface plasmon resonance response.

Main Results:

• The SPR biosensor detected ampicillin in real-time within a concentration range of 2.5-1000 μmol L⁻¹, with a limit of detection of 1 μmol L⁻¹.
• The aptasensor demonstrated high selectivity, distinguishing ampicillin from other antibiotics and drugs.
• The method was successfully applied to detect ampicillin in river water samples.

Conclusions:

• The developed electrochemical SPR aptasensor provides a sensitive, selective, and label-free platform for ampicillin detection.
• The hybrid electrochemical-SPR approach enhances the monitoring of biochemical processes, specifically antibiotic residue analysis.
• This method holds promise for environmental and food safety monitoring of ampicillin residues.