Binding assay for cholera toxin based on sequestration electrochemistry using lactose labeled with an electroactive...

Area of Science:

• Electrochemistry
• Biosensors
• Analytical Chemistry

Background:

• Cholera toxin (CT) poses a significant public health threat, necessitating sensitive and rapid detection methods.
• Existing CT detection methods can be complex and time-consuming, requiring separation steps.
• Electrochemical techniques offer potential for sensitive and label-free or simple-label detection strategies.

Purpose of the Study:

• To develop a simple and sensitive electrochemical binding assay for cholera toxin (CT).
• To utilize lactose labeled with daunomycin as an electroactive probe for CT detection.
• To investigate the performance of different electrode materials for the assay.

Main Methods:

• Development of a lactose-labeled daunomycin (LL) electroactive compound.
• Electrochemical analysis using adsorptive stripping voltammetry (AdSV).
• Investigation of glassy carbon (GC), plastic formed carbon (PFC), and carbon nanotubes paste (CNTP) electrodes.
• Demonstration of a sequestration electrochemistry assay for CT binding.

Main Results:

• The carbon nanotubes paste (CNTP) electrode exhibited the highest accumulation capacity for the labeled lactose.
• The assay detected the binding of LL to CT via a decrease in the daunomycin electrochemical signal.
• The electrochemical assay achieved a sensitive detection limit for CT of 0.5 nM (42 ng mL(-1)).
• The assay operates without a separation process to remove unbound labeled lactose.

Conclusions:

• A simple, sensitive, and rapid electrochemical assay for cholera toxin (CT) has been successfully developed.
• The use of lactose labeled with daunomycin and a CNTP electrode provides an effective detection strategy.
• This method eliminates the need for separation steps, offering a significant advantage for practical applications.