A microneedle biosensor for minimally-invasive transdermal detection of nerve agents

Abstract

A microneedle electrochemical biosensor for the minimally invasive detection of organophosphate (OP) chemical agents is described. The new sensor relies on the coupling of the effective biocatalytic action of organophosphorus hydrolase (OPH) with a hollow-microneedle modified carbon-paste array electrode transducer, and involves rapid square-wave voltammetric (SWV) measurements of the p-nitrophenol product of the OPH enzymatic reaction in the presence of the OP substrate. The scanning-potential SWV transduction mode offers an additional dimension of selectivity compared to common fixed-potential OPH-amperometric biosensors. The microneedle device offers a highly linear response for methyl paraoxon (MPOx) over the range of 20-180 μM, high selectivity in the presence of excess co-existing ascorbic acid and uric acid and a high stability sensor upon exposure to the interstitial fluid (ISF). The OPH microneedle sensor was successfully tested ex vivo using mice skin samples exposed to MPOx, demonstrating its promise for minimally-invasive monitoring of OP agents and pesticides and as a wearable sensor for detecting toxic compounds, in general.

Epidermal Tattoo Patch for Ultrasound‐Based Transdermal Microballistic Delivery

“…The decontamination experiments were carried out by using the tattoo patch to fire CeO 2 microdoses to decontaminate a skin phantom from the nerve agent methyl paraoxon. This organophosphate agent is of serious concern due to its widespread availability as a pesticide and potential misuse as a chemical warfare agent . The microballistic decontamination process was quantified by the recovered absorption peak signal of methyl paraoxon under different experimental conditions ( Figure A).…”

Silk/polyols/GOD microneedle based electrochemical biosensor for continuous glucose monitoring

“…These examples demonstrated that many researches had been concerted on the development of long-term detection systems, including crosslinking with glutaraldehyde, 23 mixing with BSA before including cross-linking with glutaraldehyde, 24 drop-casting, 14 layer assembly modify electrode. 14,[25][26][27][28][29][30] As we can see, linear detection cover physiological range could achieve, but longterm monitoring and store stability is denitely lower than that obtained with silk/D-sorbitol microneedle. Silk is a unique protein biopolymer, with six hydrophobic to one hydrophilic amino acid.…”

Printing Flexible and Hybrid Electronics for Human Skin and Eye‐Interfaced Health Monitoring Systems

“…Tissue‐injectable sensors that can penetrate the skin or eye by means of needles provide the ability to access and analyze the internal body electrophysiological activities and chemistries, which otherwise cannot be achieved by using the surface‐interfaced sensors. These injectable monitoring can capture the electrophysiological signals from organs and neurons as well as the concentration of electrolytes, salts, glucose, and lactate from interstitial fluids and bloods, providing many advantages over the other indirect measurements in terms of accuracy and capability of the real‐time monitoring without significant time lag . These injectable sensors have emerged to serve as alternatives to implantable devices for less invasive and unobtrusive monitoring, and thereby eliminating the need of any surgical procedures.…”