[Electrochemical sensor for acetaminophen based on layer-by-layer self assembly technique].

A novel type of carbon nanotube-coated Au nanoparticle and [bmim]BF4 composite modified glassy carbon electrode was fabricated by a layer-by-layer self-assembly technique. The electrochemical performance of acetaminophen (ACOP) on the modified electrode was investigated by cyclic voltammetry. The Nafion/GNPs/RTIL/MWNTs/GC electrode showed an excellent electrocatalytic activity for the oxidation of ACOP and accelerated electron transfer between the electrode and ACOP. For ACOP, the reversible electrochemical process was observed on the Nafion/GNPs/RTIL/MWNTs/GC electrode, while irreversible electrochemical process occurred on the GC electrode. For the Nafion/GNPs/RTIL/MWNTs/GC electrode, the anodic peak potential of ACOP was moved from 0.562 V to 0.413 V, with a potential drop of 149 mV. At the same time, the reduction peak potential was 0.384 V, and the potential difference was only 29 mV. It was shown that the modified electrode possessed higher electrocatalytic activity and more sensitive effect for the detection of ACOP than both MWNTs/GC electrode and GC electrode. The effects of the different experimental conditions on the electrochemical behaviors of ACOP were explored. Under the optimum conditions of preparation and experimental, the linear calibration curves of ACOP were obtained in a wide range of 2 x 10(-1) to 4.0 x 10(-4) mol x L(-1) with a correlation coefficient 0.999 2 and a detection limit of 2.6 x 10(-8) mol x L(-1) (the ratio of signal to noise, 3:1). The recovery rate was 97.9%-100.8%. This method can be used to determine ACOP in paracetamol tablets with satisfactory results.

A novel sensor based on electrochemical polymerization of diglycolic acid for determination of acetaminophen.

Diglycolic acid (DA) polymer was coated on glassy carbon (GC) electrode by cyclic voltammetry (CV) technique for the first time. The electrochemical performances of the modified electrode were investigated by CV and electrochemical impedance (EIS). The obtained electrode showed an excellent electrocatalytic activity for the oxidation of acetaminophen (ACOP). A couple of well-defined reversible electrochemical redox peaks were observed on the ploy(DA)/GC electrode in ACOP solution. Compared with bare GC electrode, the oxidation peak potential of ACOP on ploy(DA)/GC electrode moved from 0.289 V to 0.220 V. Meanwhile, the oxidation peak current was much higher on the modified electrode than that on the bare GC electrode, indicating DA polymer modified electrode possessed excellent performance for the oxidation of ACOP. This kind of capability of the modified electrode can be enlisted for the highly sensitive and selective determination of ACOP. Under the optimized conditions, a wide linear range from 2 × 10(-8) to 5.0 × 10(-4)M with a correlation coefficient 0.9995 was obtained. The detection limit was 6.7 × 10(-9)M (at the ratio of signal to noise, S/N=3:1). The modified electrode also exhibited very good stability and reproducibility for the detection of ACOP. The established method was applied to the determination of ACOP in samples. An average recovery of 100.1% was achieved. These results indicated that this method was reliable for determining ACOP.