High-performance electrochemical detection of tryptophan based on CoO-functionalized urchin-like MnO2 on nitrogen-doped g-C3N4

초록

A high-performance electrochemical sensing platform was engineered for the sensitive and selective detection of tryptophan (Trp) using a composite comprising cobalt oxide-functionalized hollow urchin-like manganese dioxide (CoO-MnO2) integrated with nitrogen-doped graphitic carbon nitride (N-g-C3N4). The hybrid nanostructure was synthesized via a hydrothermal method followed by annealing, resulting in a porous 3D architecture with enhanced surface area, redox activity, and electrical conductivity. Morphological and structural analyses confirmed the successful formation of a well-integrated nanocomposite with uniform dispersion of cobalt and manganese species and strong interfacial contact with the N-g-C3N4 support. Electrochemical studies demonstrated efficient catalytic oxidation of Trp, featuring a wide linear response range (0.1-300 mu M), a low detection limit (0.034 mu M), and high sensitivity, particularly under chronoamperometric conditions. The sensor exhibited excellent selectivity, repeatability (RSD = 3.2 %), and reproducibility (RSD = 3.8 %), with stable response retention of 89.4 % over eight weeks. Practical applicability was validated through recovery studies in human plasma samples, with results ranging from 94.0 % to 103.4 %. These findings highlight the potential of the CoO-MnO2@N-g-C3N4 sensor as a robust platform for real-time monitoring of Trp in clinical settings.

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