A voltammetric Rhodotorula mucilaginosa modified microbial biosensor for Cu(II) determination.

It is the first report about the usage of Rhodotorula mucilaginosa as a biomaterial to construct a microbial biosensor based on carbon paste for determination of copper. Cu(II) was preconcentrated electrode surface at open circuit and then detected with electrochemical techniques, including Cyclic Voltammetry (CV) and Differential Pulse Stripping Voltammetry (DPSV). Some parameters such as pH of preconcentration solution, preconcentration time, scan rate and effect of interfering heavy metal ions were carried out for optimum responses. The best defined cathodic peak was obtained at pH 5 with 0.05 M NaNO(3) and a scan rate of 100 mV/s. The linear range for the developed microbial biosensor was found in the range of 1.0 x 10(-7) and 1.0 x 10(-5)M (0.0064 and 0.64 mg/L) at the response time of 15 min (R(2)=0.98). The easy fabrication, sensitivity, low cost and fast response time showed the advantages of the biosensor to conventional techniques.