Catalytic effects of magnetic and conductive nanoparticles on immobilized glucose oxidase in skin sensors

LILIAN CELESTE ALARCON SEGOVIA; AMAY J. BANDODKAR; JOHN A. ROGERS; IGNACIO RINTOUL

NANOTECHNOLOGY

IOP PUBLISHING LTD

Lugar: Londres; Año: 2021 vol. 32

0957-4484

Wearableskin sensors is a promising technology for real-time health caremonitoring. They are of particular interest for monitoring glucose indiabetic patients. The concentration of glucose in sweat can be morethan two orders of magnitude lower than in blood. In consequence, thescientific and technological efforts are focused in developing newconcepts to enhance the sensitivity, decrease the limit of detection(LOD) and reduce the response time (RT) of glucose skin sensors. Thiswork explores the effect of adsorbed superparamagnetic (MNPs) andconductive nanoparticles (CNPs) on carbon nanotube substrates(CNTs) used to immobilize glucose oxidase enzyme in the workingelectrode of skin sensors. MNPs and CNPs are made of magnetite andgold, respectively. The performance of the sensors was tested instandard buffer solution, artificial sweat, fresh sweat and on theskin of a healthy volunteer during an exercise session. In the caseof artificial sweat, the presence of MNPs accelerated the RT from 7 sto 5 s at the expense of increasing the LOD from 0.017mM to 0.022 mMwith slight increase of the sensitivity from 4.90 μAmM-1cm-2to 5.09 μAmM-1cm-2.Thepresence of CNPs greatly accelerated the RT from 7 s to 2 s andlowered the LOD from 0.017 mM to 0.014 mM at the expense of a greatdiminution of the sensitivity from 4.90 μAmM-1cm-2to 4.09μAmM-1cm-2.These effects were explained mechanistically by analyzing the changesin the concentration of free oxygen and electrons promoted by MNPsand CNPs in the CNTs and its consequences on the the glucoseoxidation process.p { margin-bottom: 0.25cm; direction: ltr; color: #00000a; line-height: 120%; text-align: left; orphans: 0; widows: 0 }p.western { font-family: "Liberation Serif", "Times New Roman", serif; font-size: 12pt; so-language: en-US }p.cjk { font-family: "Droid Sans Fallback"; font-size: 12pt; so-language: zh-CN }p.ctl { font-family: "FreeSans"; font-size: 12pt; so-language: hi-IN }