Portable detection of clenbuterol using a smartphone-based electrochemical biosensor with electric field-driven acceleration

We have developed a fast, highly sensitive and low-cost biosensing system for the detection of clenbuterol (CLB), using a homemade mobile electrochemical device with an electric field-driven acceleration strategy. This system consists of an embedded circuit in smartphone for signal processing and a screen-printed carbon electrode (SPCE) modified with multi-walled carbon nanotubes (MWNTs) and goat anti mouse-immunoglobulin G (IgG) sensing layer (MWNTs-I-layer). CLB monoclonal antibody was assembled through its binding to the surface-confined antibody. Such modified electrodes were used for rapid and sensitive amperometric immunosensing detection of CLB. Horseradish peroxidase-coupled CLB (CLB-HRP) competed with free CLB in the samples to bind the monoclonal antibody. By using this mobile system, we could detect CLB ranging from 0.3 ng ⋅ mL− 1 to 100 ng ⋅ mL− 1 with the detection limit of 0.076 ng ⋅ mL− 1. The whole competitive-type detection process was finished within 6 min. We expect this device can meet the requirements for field detection of various food security-related species.