Wearable Electrochemical Microneedle Sensors Based on the Graphene-Silver-Chitosan Nanocomposite for Real-Time Continuous Monitoring of the Depression Biomarker Serotonin

Abstract

Wearable microneedle-based electrochemical sensor technologies are promptly growing due to their unique capabilities, such as minimally invasive, painless, real-time, continuous monitoring, etc. Strong disruptions or imbalances of neurotransmitter systems are associated with many chronic diseases and mental disorders, including Parkinson’s, depression, anxiety, memory loss, significant changes in weight, and chronic physical or emotional stress. The captivating advantages of the wearable microneedle-based sensor enable continuous monitoring of various biomarkers and pharmaceutical drugs in interstitial fluid (ISF). In this present work, we have developed a sensor for continuous monitoring of the biologically important neurotransmitter Serotonin (5-hydroxytryptamine, 5-HT) through a microneedle patch. The new microneedle sensor array relies on Ag/rGO-modified carbon paste microneedle electrodes for square wave voltammetry and amperometry detection of the 5-HT target. Such real-time orthogonal sensing offers distinct, unique information and the desired analytical performance. The surfaces of the working electrodes have been characterized with electroanalytical and surface morphological techniques. The developed sensor was able to detect 5-HT target from phosphate-buffered saline buffer within linear ranges of 3–21 and 6–60 μM (both short and long ranges) with well-defined linearity. The continuous monitoring and biofouling studies of the microneedle sensor were demonstrated in artificial ISF containing bovine serum albumin by using chronoamperometry. The sensor exhibited linearity in the range of 13.5–95 μM. The long-term monitoring capability of the sensor was demonstrated in an artificial ISF medium. The specificity of the sensor was exhibited in the presence of potentially interfering substances. The excellent performance shown in the skin-mimicking model proved that the microneedle sensor platform holds considerable promise for real-time detection of the important neurotransmitter 5-HT in the ISF.

Nanoscale materials at work: Mapping emerging applications in energy, medicine, and beyond

“…510 Patent publications show similar use/applicability of cellulose [511][512][513] and chitosan 514,515 including metal organic framework (MOF)-multi-walled carbon nanotube (MWCNT)/chitosan composites for electrochemical detection of tryptophan enantiomers. 516 as well as metals 508 and metal oxides. 510 Patent publications show similar use/applicability of cellulose [511][512][513] and chitosan 514,515 including metal organic framework (MOF)-multi-walled carbon nanotube (MWCNT)/chitosan composites for electrochemical detection of tryptophan enantiomers.…”

“…The use of chitosan has been explored in sensors across several biomedical applications including in wearable sensors for health monitoring 506,507 including continuous monitoring of the neurotransmitter serotonin considered a biomarker for depression. 508 Often chitosan is used in conjunction with other materials in the fabrication of these sensors including synthetic polymers such as polyaziridne 509 Among emerging polymers, synthetic polymers tend to outnumber natural polymers with cellulose and chitosan being the only natural polymers featured in the top 15 for both journal and patent publications (Figure 23). Examples include journal publications describing the use of cellulose in electrochemical, 501 flexible strain 502 and chemosensors 503 often as nanofibers and in combination with other materials (including synthetic polymers) used for applications such as health monitoring, 504 heavy metal detection 503 and in the food industry 505 amongst others.…”

“…The use of chitosan has been explored in sensors across several biomedical applications including in wearable sensors for health monitoring 506,507 including continuous monitoring of the neurotransmitter serotonin considered a biomarker for depression. 508 Often chitosan is used in conjunction with other materials in the fabrication of these sensors including synthetic polymers such as polyaziridne 509 as well as metals 508 and metal oxides. 510 Patent publications show similar use/applicability of cellulose [511][512][513] and chitosan 514,515 including metal organic framework (MOF)-multi-walled carbon nanotube (MWCNT)/chitosan composites for electrochemical detection of tryptophan enantiomers.…”

SERS-Based Microneedle Biosensor for In Situ and Sensitive Detection of Tyrosinase

“…Recognized for its minimal tissue impact, swift recovery time, and patient-friendly nature, microneedle technology has attracted significant interest and has emerged as a promising avenue for accurate clinical diagnostics and health monitoring. It also demonstrates considerable potential in the detection of subcutaneous biomarkers, efficiently tracking a range of skin-underlying biomarkers such as glucose, lactate, neurotransmitters, cholesterol, glycine, and pH through a user-friendly, swift, and non-invasive approach [29][30][31][32][33][34].…”