Electrochemical immunosensor based on polyaniline/poly (acrylic acid) and Au-hybrid graphene nanocomposite for sensitivity enhanced detection of salbutamol

An ultrasensitive electrochemical immunosensor based on nanogold particles (nano-Au), Prussian Blue (PB), polyaniline/poly (acrylic acid) (PANI (PAA)) and Au-hybrid graphene nanocomposite (AuGN) has been developed for the detection of salbutamol (SAL). Nano-Au, PB and PANI (PAA)-incorporated film was used to enhance the electroactivity, stability and catalytic activity for hydrogen reduction of the electrode. AuGN was used to immobilise chitosan, nano-Au and horseradish peroxidase-anti-SAL antibody (HRP-AAb). The resulting nanostructure (AuGN-HRP-AAb) was used as the label for the immunosensor. This is attributed to the high surface-to-volume ratio of graphene that allows the immobilisation of a high level of chitosan, nano-Au and HRP-AAb and its good electrical conductivity which can improve the electron transfer among HRP, H2O2 and electrode. Under the optimized conditions, a calibration plot for SAL was obtained with a linear range between 0.08 ng/mL and 1000 ng/mL (r = 0.9955). The detection limit was 0.04 ng/mL. The immunosensor was examined in real feed and pork samples for the analysis of SAL.