A novel sensor for nicotinamide adenine dinucleotide based on poly-3, 4-ethylenedioxythiophene-coordinated gold nanoparticle-functionalized acupuncture needle microelectrode

Reduced nicotinamide adenine dinucleotide (NADH) plays crucial roles in maintaining cell growth and differentiation, cytoprotection and energy metabolism. And it is imperative to precisely monitor the variable quantity of NADH. Herein, the connotative feature of acupuncture needle (AN) was explored as electrochemical matrix. Poly-3, 4-ethylenedioxythiophene-liganded gold nanoparticle modified AN electrode (ANE/AuNPs/PEDOT) was prepared via a simple electrosynthesis technology. Working together by charge transfer and reaction has a strong response to the electron-transfer of “N” in NADH, which is coordinately presented as a current peak. Interestingly, the behavior of electron-transfer was affected by ambient environment. After the conditional optimization, the fabricated sensor exhibited good linear range of 20 ∼ 500 μmol/L with a detection limit of 18.5 μmol/L. In addition, the sensor can be successfully applied to analysis NADH in serum. Furthermore, the microelectrode exhibits the real-time monitor ability for NADH that released from MDA-MB231 cells. This sensor also possesses the significant performance of high selectivity, stability and reproducibility. Based on the acupuncture history, the developed ANE should be a fascinating microsensor besides the low price, fast response and user-friendly operation.