In Vivo Electrochemical Sensors for Neurochemicals: Recent Update

Abstract

In vivo electrochemical sensing based on implantable microelectrodes is a strong driving force of analytical neurochemistry in brain. The complex and dynamic neurochemical network sets stringent standards of in vivo electrochemical sensors including high spatiotemporal resolution, selectivity, sensitivity, and minimized disturbance on brain function. Although advanced materials and novel technologies have promoted the development of in vivo electrochemical sensors drastically, gaps with the goals still exist. This Review mainly focuses on recent attempts on the key issues of in vivo electrochemical sensors including selectivity, tissue response and sensing reliability, and compatibility with electrophysiological techniques. In vivo electrochemical methods with bare carbon fiber electrodes, of which the selectivity is achieved either with electrochemical techniques such as fast-scan cyclic voltammetry and differential pulse voltammetry or based on the physiological nature will not be reviewed. Following the elaboration of each issue involved in in vivo electrochemical sensors, possible solutions supported by the latest methodological progress will be discussed, aiming to provide inspiring and practical instructions for future research.

Solid-Contact Ion-Selective Electrodes: Response Mechanisms, Transducer Materials and Wearable Sensors

“…Over the past few decades, we have witnessed the development of ISEs from LC to SC that has miniaturized and integrated the ISEs. In addition to the wearable sensors, SC-ISEs could be further intensively explored for in vivo investigations at cell, tissue or organ level [103][104][105][106][107]. More scientific challenges and the promise of practical application provide tremendous space and the next hot-spot for the SC-ISEs.…”

Clinically oriented Alzheimer's biosensors: expanding the horizons towards point-of-care diagnostics and beyond

“…Similar concept of electrochemical application was extended using silk broin material by Liu et al on the development of POC device for Ab detection based on blood sample. 226 In addition, a thorough discussion on state-of-the-art of microelectrode-based in vivo neurochemicals sensing has been discussed in a review by Xu et al 227 A microelectrode principle was further employed by Peng et al using carbon bre to monitor the superoxide anion radical (O 2 c À ) which directly correlate with production of reactive oxygen species-induced Ab. 224 They engineered ionic-liquid polymer with carbon nanotubes to mask the immobilized oxide dismutase (i.e., catalysing O 2 c À into peroxide species) from the enzyme leakage thereby, achieving better sensitivity (Fig.…”

Addressing the Selectivity of Enzyme Biosensors: Solutions and Perspectives

“…The recent years witnessed a tremendous progress in the development of enzymatic biosensors as wearable devices for the non-invasive analysis of biomarkers in physiological fluids [ 2 ], for example for the detection of glucose, lactate, alcohol and uric acid analysis in sweat [ 3 ]. The in vivo analysis is another area that has seen progress in designing electrochemical enzyme biosensors with enhanced selectivity [ 4 , 5 , 6 ] best illustrated by implantable electrodes for the detection of neurotransmitters in the brain [ 7 ]. In addition various biosensors were developed for food analysis, targeting the detection of pesticides, glucose, lactate, glycerol (e.g., for monitoring fermentative processes), biogenic amines (for evaluating the freshness of fish and meat), bisphenol A, etc.…”