RESUMEN
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.
Asunto(s)
Compuestos de Anilina , Técnicas Biosensibles , Oro , Plomo , Nanopartículas del Metal , Peroxidasa , Tropomiosina , Compuestos de Anilina/química , Biocatálisis , Técnicas Biosensibles/métodos , Técnicas Electroquímicas/métodos , Microelectrodos , Peroxidasa/química , Reproducibilidad de los Resultados , Tropomiosina/sangre , Tropomiosina/metabolismoRESUMEN
Enzyme-linked immunosorbent assay (ELISA) is a popular detection technique for the screening and diagnosis of diseases. The sensitivity of ELISA can be increased by the incorporation of nanoparticles. Through this article, we discuss the utilization of nanoparticles in ELISA. Nanoparticles possess an intrinsic biological peroxidase-like activity which allows it to act as an enzyme mimic for the development of an improved analysis method. Different nanoparticles (gold nanoparticles, silver nanoparticles, etc.) carry different peroxidase-mimic characteristics. Besides this, nanoparticles can also perform as a colorimetric substrate in ELISA where it gives a more prominent color change compared to the commonly used colorimetric substrate TMB. This article also focuses on the mechanisms behind this color change including aggregation, in situ nanoparticle growth, seeding, and etching.
Asunto(s)
Técnicas Biosensibles/métodos , Colorimetría/métodos , Inmunoensayo/métodos , Nanopartículas/química , Ensayo de Inmunoadsorción Enzimática/métodos , Oro , Nanopartículas del Metal/química , Peroxidasa , Sensibilidad y Especificidad , Plata , Especificidad por SustratoRESUMEN
Nanoparticles have been widely developed and shown to have intrinsic enzymatic ability, and are used in biosensors. Compared to biological enzymes used in biosensors, which are expensive and tedious to harvest, enzyme-mimic nanoparticles or nanozymes are both more stable and sensitive. An important area in this work is the development of a simple detection principle of immunosensor based on the one-step synthesis of silver nanoparticle seeded onto a gold core. The gold-silver core-shell nanoparticle acts as a peroxidase mimic, which enables them to oxidise 3,3',5,5'-tetramethylbenzidine (TMB) with H2O2, giving a colourimetric response. Herein, the analytical performance of the nanozyme is exploited to detect haptoglobin as a model analyte in a 96-well plate and measured the colourimetric product using spectrophotometer. The sensitivity of the immunosensor was as low as 100 pg mL-1. The viability of our immunosensor was shown to have good selectivity and satisfactory recovery in real serum samples.