High-Sensitivity Electrochemiluminescence Biosensor Based on Silver-Carbon Nitride for the Detection of Dopamine utilizing Enhancement Effects

An ultrasensitive electrochemiluminescence (ECL) biosensor for detecting dopamine was successfully constructed based on chemically stable and easily available carbon nitride materials as signal probe. Herein, the newly synthesized silver-carbon nitride (Ag-g-C3N4) nanocomposites were modified on the glassy carbon electrode (GCE) surface via the film-forming properties of chitosan, generating a relative weak ECL signal. When dopamine was added to the detection solution containing 80 mM S2O82-, a strong ECL signal was observed, which might be ascribed to the fact that the amino group of dopamine promoted the coreactant conversion of S2O82- into SO4.-, leading to enhanced ECL intensity. Under optimal experimental conditions, the as-prepared ECL sensor exhibited a wide linear range from 0.015 to 150 mu M and a low detection limit of 0.005 mu M for dopamine determination. Moreover, the recovery experiments exhibited that the sensor can be applied to precisely detect dopamine in real serum samples, suggesting that the as-prepared ECL sensor established a new method and a promising platform for sensitive dopamine evaluation.