Multiporous molybdenum carbide nanosphere as a new charming electrode material for highly sensitive simultaneous detection of guanine and adenine.

By introduction of Mo metal species (molybdenum-based polyoxometalates) into the Cu-MOF as co-precursor, molybdenum carbide nanosphere (MoxC@C) was prepared via a simple calcining routine and a further etching the metallic Cu process. The obtained MoxC@C showed a unique structure where well-dispersed MoxC nanoparticles (NPs) were encapsulated in porous carbon matrix. As-fabricated novel 3D porous architecture MoxC@C nanosphere exhibited a potent and persistent electro-oxidation behavior followed by well-separated oxidation peaks (peak to peak voltage is about 350 mV) toward adenine (A) and guanine (G) by differential pulse voltammetry (DPV). This excellent electrochemical performance can be attributed to the unique structure and composition of 3D MoxC@C. Furthermore, 3D MoxC@C also revealed high selectivity and sensitivity, good reproducibility, excellent stability and anti-interference ability. The calibration curves for quantitive analysis of G and A were obtained: 0.03-122 µM, and 0.02-122 µM, respectively, the detection limits were 0.0085 µM, 0.008 µM, respectively. The proposed procedure was successfully applied to detect G and A in human urine and serum samples with satisfactory recovery, which manifests its viability application for practical analysis.