Gold-microrods/Pd-nanoparticles/polyaniline-nanocomposite-interface as a peroxidase-mimic for sensitive detection of tropomyosin

In this study, Gold-microrods (AuMRs), Pd-nanoparticles (PdNPs), and Polyaniline (PANI) nanocomposite-interface was fabricated on the screen-printed carbon-microelectrode (SPE). Each layer of the interface was characterised using field emission-scanning electron microscopy (FE-SEM) and cyclic voltammetry (CV). The fabricated SPE/AuMRs/PdNPs/PANI interface demonstrated the highest electronic current and showed excellent peroxidase-mimic towards H2O2 using chronoamperometry (CA). Furthermore, the SPE/AuMRs/PdNPs/PANI interface was utilised for the construction of a highly sensitive label-free electrochemical biosensor for the detection of Tpm in seafood samples. Label-free electrochemical detection of the Tpm was performed using both CA and differential pulse voltammetry (DPV) techniques. Preliminary data showed that both methods could detect Tpm as low as 0.01 pg/mL. Moreover, the developed biosensor for the detection of Tpm demonstrated excellent selectivity, high reproducibility and longer stability with an evident potential to detect Tpm in real seafood samples. •AuMRs/PdNPs/PANI nanocomposite-interface was fabricated on microelectrode.•Electrocatalytic characteristics and electroactive surface area was improved.•AuMRs/PdNPs/PANI acted as a peroxidase-mimic towards H2O2.•Both CA and DPV was used for the sensitive detection of the Tropomyosin.•Both CA and DPV techniques demonstrated low LoD 0.01 pg/mL for Tropomyosin.