Amperometric immunosensor for nonylphenol determination based on peroxidase indicating reaction.
ABSTRACT Novel immunosensor for nonylphenol (NP) determination has been developed by immobilization of specific antibodies together with horseradish peroxidase on the surface of carbon screen-printed electrode. The signal of the immunosensor is generated by the involvement of NP accumulated in the peroxidase oxidation of mediator (Methylene Blue, hydroquinone or iodide). This results in the increase of the signal recorded by linear-sweep voltammetry. The sensitivity of the detection depends on the nature of mediator, its concentration and incubation period. Cross-selectivity of the response toward readily oxidized phenolic compounds has been determined. The immunosensor developed makes it possible to detect from 20 microgL(-1) to 44 mgL(-1) of NP with detection limit 10 microgL(-1) of NP.
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ABSTRACT: A facile electrochemical sensor for the determination of nonylphenol (NP) was fabricated in this work. Cetyltrimethylammonium bromide (CTAB), which formed a bilayer on the surface of the carbon paste (CP) electrode, displayed a remarkable enhancement effect for the electrochemical oxidation of NP. Moreover, the oxidation peak current of NP at the CTAB/CP electrode demonstrated a linear relationship with NP concentration, which could be applied in the direct determination of NP. Some experimental parameters were investigated, such as external solution pH, mode and time of accumulation, concentration and modification time of CTAB and so on. Under optimized conditions, a wide linear range from 1.0 × 10-7 mol·L-1 to 2.5 × 10-5 mol·L-1 was obtained for the sensor, with a low limit of detection at 1.0 × 10-8 mol·L-1. Several distinguishing advantages of the as-prepared sensor, including facile fabrication, easy operation, low cost and so on, suggest a great potential for its practical applications.Sensors 01/2013; 13(1):758-68. DOI:10.3390/s130100758 · 2.05 Impact Factor
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ABSTRACT: AbstractA ternary composite material based on Prussian blue, single‐walled carbon nanotubes and 1‐butyl‐3‐methylimidazolium hexafluorophosphate was prepared and tested for electrochemical detection of H2O2. The sensor allows amperometric detection of H2O2 at −0.05 V, with a sensitivity of 137 mA M−1⋅cm−2. The nanocomposite provides a favorable microenvironment for immobilization of horseradish peroxidase (HRP). Determination of xenoestrogenic compounds was performed by enzymatic oxidation at the surface of modified screen printed biosensor in the presence of H2O2. The developed electrochemical biosensors exhibited high sensitivity, low detection limits, good operational and storage stability, for detection of 4‐t‐butylphenol, 4‐t‐octylphenol, 4‐n‐nonylphenol and 4‐n‐nonylphenol ethoxylate.Electroanalysis 12/2012; 24(12). DOI:10.1002/elan.201200390 · 2.50 Impact Factor
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ABSTRACT: The electrochemical determination of nonylphenol (NP) using differential pulse voltammetry (DPV) is developed based on a reduced graphene-DNA hybrid-modified glassy carbon electrode (GR-DNA/GCE). The electrochemical oxidation of NP at the GR-DNA/GCE is shown to be a one-electron and one-proton process, and due to the synergic effect of GR and DNA, the GR-DNA/GCE has 4.87, 2.76 and 2.09 times higher current response than bare GCE, DNA/GCE, and GR/GCE, respectively. Using DPV in the 0.1 mol L-1 acetate buffer solution at 0.1 V and with a 300 s accumulation time (pH=4.6), the GR-DNA/GCE exhibits a linear current response towards the electrochemical oxidation of NP in the concentration range of 5.0×10-8 to 4.0×10-6 mol L-1 and a detection limit of 1.0×10-8 mol L-1 (S/N=3). In addition, this GR-DNA/GCE also indicates high selectivity and reproducibility, and can be successfully used to determine the presence of NP in Asian Clams and natural water samples with comparative sensitivity to high-performance liquid chromatography, and with recoveries ranging from 95% to 103%, showing its practical prospects in the determination of NP in real samples.Journal of electroanalytical chemistry 08/2013; 703. DOI:10.1016/j.jelechem.2013.05.029 · 2.87 Impact Factor