Enbo Shangguan

A novel electrochemical sensor based on FeS anchored reduced graphene oxide nanosheets for simultaneous determination of dopamine and acetaminophen.

In this paper, FeS nanoparticles anchored on reduced graphene oxide (rGO) nanosheets are synthesized via a facile direct-precipitation method. For the first time, a novel electrochemical sensor is developed based on FeS/rGO nanosheets modified glassy carbon electrode (GCE). It has been proved that the resultant FeS/rGO/GCE sensor is very suitable for the individual and simultaneous measurement of dopamine (DA) and acetaminophen (AC) and delivers excellent anti-interference ability to ascorbic acid (AA) and uric acid (UA). Under optimum conditions with differential pulse voltammetry method, a broad linear response versus the concentrations of DA and AC has been observed in the ranges of 2.0 to 250.0μM and 5.0 to 300.0μM, respectively. The detection limits for DA and AC are 0.098μM and 0.18μM, respectively. Furthermore, the as-obtained sensor has been successfully utilized in real samples and satisfactory results have been achieved. Consequently, by virtue of its outstanding electrocatalytic activity, excellent sensitivity, and long time stability, the as-obtained FeS/rGO modified electrode can be considered as a new promising DA and AC sensor.

The effect of acidity, hydrogen bond catalysis and auxiliary electrode reaction on the oxidation peak current for dopamine, uric acid and tryptophan

A pre-anodized inlaying ultra-thin carbon paste electrode on a 316L stainless steel matrix (316L-PAIUCPE) was prepared and used for simultaneous determination of dopamine (DA), uric acid (UA) and tryptophan (Trp). The mechanism by which the acidity affects the size of the oxidation peak currents (ip) for DA, UA and Trp was discussed with respect to the strength of the hydrogen bonding or electrostatic interactions between DA, UA, Trp and the negatively charged functional groups at the surface of 316L-PAIUCPE, and the reduction reaction at the auxiliary electrode. Under optimized experimental conditions, the oxidation peak currents increased linearly with the concentrations of DA, UA and Trp in the range of 0.4–200, 0.5–150 and 0.1–200 μmol L−1, respectively. The detection limits for DA, UA and Trp were 6.8 × 10−8, 4.5 × 10−8, and 5.3 × 10−8 mol L−1 in PBS buffer solution (pH = 5.00), respectively. This method was successfully used to determine the concentrations of DA, UA, and Trp in different samples.