Hollow microneedle-based sensor for multiplexed transdermal electrochemical sensing.
The development of a minimally invasive multiplexed monitoring system for rapid analysis of biologically-relevant molecules could offer individuals suffering from chronic medical conditions facile assessment of their immediate physiological state. Furthermore, it could serve as a research tool for analysis of complex, multifactorial medical conditions. In order for such a multianalyte sensor to be realized, it must be minimally invasive, sampling of interstitial fluid must occur without pain or harm to the user, and analysis must be rapid as well as selective. Initially developed for pain-free drug delivery, microneedles have been used to deliver vaccines and pharmacologic agents (e.g., insulin) through the skin. Since these devices access the interstitial space, microneedles that are integrated with microelectrodes can be used as transdermal electrochemical sensors. Selective detection of glucose, glutamate, lactate, hydrogen peroxide, and ascorbic acid has been demonstrated using integrated microneedle-electrode devices with carbon fibers, modified carbon pastes, and platinum-coated polymer microneedles serving as transducing elements. This microneedle sensor technology has enabled a novel and sophisticated analytical approach for in situ and simultaneous detection of multiple analytes. Multiplexing offers the possibility of monitoring complex microenvironments, which are otherwise difficult to characterize in a rapid and minimally invasive manner. For example, this technology could be utilized for simultaneous monitoring of extracellular levels of, glucose, lactate and pH, which are important metabolic indicators of disease states (e.g., cancer proliferation) and exercise-induced acidosis.
Joint Department of Biomedical Engineering, University of North Carolina and North Carolina State University, USA.
Philip R
PR
Miller
Shelby A
SA
Skoog
Thayne L
TL
Edwards
David R
DR
Wheeler
Xiaoyin
X
Xiao
Susan M
SM
Brozik
Ronen
R
Polsky
Roger J
RJ
Narayan
D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D055664:Electrochemical Techniques / Q000295:instrumentation* / Q000379:methods; D008845:Microinjections / Q000295:instrumentation*; D009339:Needles