A sensitive and selective electrochemical sensor based on N, P-Doped molybdenum Carbide@Carbon/Prussian blue/graphite felt composite electrode for the detection of dopamine.

In this paper, a composite electrode of N,P-doped Mo ₂ C@C/Prussian blue (PB)/graphite felt (N,P-Mo ₂ C@C/PB/GF) was prepared by a simple method and used for sensitive and effective detection of dopamine (DA). N,P-doped Mo ₂ C nanospheres were prepared by using phosphomolybdic acid (PMo ₁₂ ) as an initiator to promote the polymerization of polypyrrole. Such nanospheres were used to accelerate the deposition process of PB from K ₃ [Fe(CN) ₆ ] and FeCl ₃ in solution. The N,P-Mo ₂ C@C/PB nanohybrid was then anchored to GF in order to obtain the electrochemical sensor. Two linear ranges were extrapolated for dopamine detection: from 0.18 to 30 μmol L ^-1 with a sensitivity of 0.268 μA μmol ^-1 , and from 30 to 280 μmol L ^-1 with a sensitivity of 0.045 μA μmol ^-1 . The device showed a detection limit as low as 0.011 μmol L ^-1 , an excellent selectivity to DA over common interfering analytes, and a favorable long-time stability. Finally, the sensor was used for quantitative analysis of DA in the 10-fold dilution of human serum (10%) and exhibited a satisfactory recovery.
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