MWCNT-polypyrrole 코어-쉘 나노와이어를 이용한 비효소식 전기화학적 락테이트 검지 센서

Abstract

Lactate plays an important role as a biochemical indicator for sports medicine and clinical diagnosis. The detection of lactate in sweat is a promising technique without any intrusive inconvenience or risk of infection. In this study, we present a non-enzymatic electrochemical detection method for lactate in human sweat utilizing a multi-wall carbon nanotube (MWCNT)-polypyrrole core-shell nanowire. Polypyrrole is uniformly coated onto the surface of MWCNTs utilizing surface modification and chemical oxidation polymerization. A chronoamperometric study at 0.68 V in a 0.1 M Na2SO4 electrolyte reveals good sensing performance for lactate with a high sensitivity of 2.9 μA mM−1 cm−2 and detection limit of 51 μM. Furthermore, the proposed nanowire exhibits excellent selectivity for lactate over interfering species, such as sodium chloride, potassium chloride, glucose, urea, and riboflavin, which coexist with lactate in sweat. Because polypyrrole is a p-type conducting polymer onto which anions are exclusively doped, leading to charge transfer, it offers selective detection for lactate anions at a specific potential while being inert to the neutral and cationic species contained in human sweat. Finally, a non-enzymatic sensor for the detection of lactate in human sweat is demonstrated by applying the MWCNT-polypyrrole core-shell nanowire to a commercial flexible electrode. The results demonstrate the potential applications of the MWCNT-polypyrrole core-shell nanowire as a non-enzymatic lactate sensor.