Perspective—The Feasibility of Continuous Protein Monitoring in Interstitial Fluid

Abstract

Real-time continuous monitoring of proteins in-vivo holds great potential for personalized medical applications. Unfortunately, a prominent knowledge gap exists in the fundamental biology regarding protein transfer and correlation between interstitial fluid and blood. In addition, technological sensing will require affinity-based platforms that cannot be robustly protected in-vivo and will therefore be challenged in longevity, fouling, and sensitivity over multi-day to week timelines. Here we use electrochemical aptamer-based sensors as a model system to discuss further research necessary to achieve continuous protein sensing.

Harvesting and manipulating sweat and interstitial fluid in microfluidic devices

“…63 Moreover, microneedle insertion can even elevate the levels of inflammatory markers in the body, eventually increasing the chances of registering false positive signals when targeting to measure such biomarkers. 67 Our group has recently demonstrated how osmosis can be utilized to prolong ISF collection (US patent #18/217392). Interfacing a high osmotic strength hydrogel and a paper channel to the back of a soft microneedle patch enables prolonged ISF sampling and flow for continuous biomarker monitoring (Fig.…”

“…Continuous and real-time detection of proteins can be achieved with aptamers as the receptor element, but sensitivity will depend on the protein molecular weight, blood-to-ISF lag time, and changes in the local ISF environment. 67,171 Up to date, this concept has been demonstrated with blood 172 and ISF (with microneedles) 173 under a microfluidic setting.…”

Editors’ Choice—Review—The Future of Carbon-Based Neurochemical Sensing: A Critical Perspective

“…Electrochemical aptamer-based (E-AB) sensors are a biosensor used for in vivo measurements capable of real-time binding to a specific target molecule and rely on reporter binding rather than target reactivity. 70 E-AB sensors have proven effective employing a redox reporter for continuous monitoring of therapeutic drugs, 71 proteins, 72 and others in biological fluids. Commonly, these sensors are fabricated on a gold substrate showing recent innovations on gold microneedles for in vivo implantation, 71 but these have even shown viability on carbon substrates like glassy carbon 73 paving the way for possible applications in FSCV.…”

Electrochemical Sensor Modified with Graphene Oxide Decorated with Copper Oxide Nanoparticles for Velpatasvir’s Monitoring in Spiked Human Plasma

“…Electrochemical methods show promising potential in TDM analysis owing to their great sensitivity, simplicity, cost efficiency, and rapidity. [3][4][5][6][7][8][9] There are different types of electrochemical techniques, like voltammetry, amperometry, conductometry, and potentiometry. [10][11][12] Voltammetric techniques entail applying varying potential to the working electrode, followed by the measurement of the resultant current.…”