Construction Of Electrochemical Sensors Base On CuS@PB Nanocomposite And Its Application In The Detection Of Ascorbic Acid

Efficient detection of biomolecules has become a tendency in the field of life sciences.With the development of nanotechnology,electrochemical sensors modified with nanocomposite showed a fast and accurate detection.Copper sulfide nanoparticles(CuS NPs)are ideal materials for signal transmission in electrochemical sensors due to good electrical conductivity,excellent chemical stability,low cost,and easy preparation.On the other hand,Prussian blue(PB)showed excellent electrical activity,large specific surface area and adjustable structure,suggesting that PB is an excellent response material in electrochemical sensors.Therefore,an electrochemical sensor based on core-shell nanostructured copper sulfide@Prussian blue nanocomposites(CuS@PB NPs)was investigated for ascorbic acid(AA)detection.The main results are presented as following:1.CuS NPs were prepared by a hydrothermal method,and the factors affecting the synthesis of CuS NPs including cooling rate and surface ligands were investigated.Transmission electron microscopy(TEM),X-ray diffraction(XRD),and dynamic light scattering(DLS)were used to characterize the CuS NPs,and the CuS NPs with appropriate morphology and particle size were optimized for subsequent preparation of nanocomposite.2.The core-shell CuS@PB NPs was firstly fabricated through in situ synthesis of PB on CuS NPs.CuS@PB NPs with different shell thicknesses were prepared by different Cu:Fe molar ratios.TEM images of CuS@PB NPs illustrated a core-shell nanostructure,and the CuS NPs are uniformly dispersed in the PB matrix with a uniform particle size and good dispersion.3.A novel electrochemical sensor was developed by using CuS@PB nanohybrid modified with glassy carbon electrode(CuS@PB/GCE).Cyclic voltammetry(CV),differential pulse voltammetry(DPV),and electrochemical impedance spectroscopy(EIS)were used to meansure the electrochemical property of CuS@PB/GCE in a three-electrode system.Those results showed that CuS@PB/GCE has a better electrocatalytic activity and electron transport rate than PB/GCE.4.The prepared CuS@PB/GCE was used for the detection of ascorbic acid(AA)by amperometric.As expected,amperometric current observations showed that CuS@PB/GCE presented a wide detection range,low detection limit,high sensitivity,good response speed and electrocatalytic stability,and good selectivity and anti-interference ability for the detection of AA.Additionally,CuS@PB/GCE showed excellent performance for AA assay in real samples,demonstrating a great prospect for quantitative detection to AA in various fields.