Polymer-based, flexible glutamate and lactate microsensors for in vivo applications

Silicon/SU8 multi-electrode micro-needle for in vivo neurochemical monitoring

“…We also adopted a design of micro-wells around electrodes creating a steric barrier for H 2 O 2 diffusion out of the well. Although the micro well design had been already proposed in previous works (Frey et al, 2010;Weltin et al, 2014), this is, to our knowledge the first study using only SU8 to create the boundaries between wells. The SU8 resist allowed a large range of possible thicknesses easily achievable by modifying photolithography conditions practical for optimizing the microwells design.…”

“…Most of the reported planar devices allowed monitoring of only one analyte with half of the microelectrodes devoted to enzymatic sensing and the other half devoted to the control of non-specific currents (Rutherford et al, 2007;Wassum et al, 2008;Weltin et al, 2014). A few reports demonstrated successful parallel recordings of choline and acetylcholine (Burmeister et al, 2008) or glutamate and non-specific (control) current (Frey et al, 2010) using multi-sensing micro-arrays without significant cross-talk between recording sites.…”

“…Planar multi-electrode biosensors have been developed for in vivo neurochemical monitoring on ceramic substrate (Bruno et al, 2006;Burmeister et al, 2000;Rutherford et al, 2007;Wassum et al, 2008), on silicon substrate (Frey et al, 2010;Ruther et al, 2008;Wassum et al, 2012Wassum et al, , 2008 and recently on polyimide substrate (Weltin et al, 2014). Silicon, widely employed in MicroElectro-Mechanical-Systems (MEMS) offers strength and elasticity necessary for construction of bioprobes.…”

Electrochemical Arrays for Bioassay Applications

“…A recent report of an in vivo flexible strip microelectrode sensor array for glutamate and lactate monitoring in tissue represents an advance [44]. The polyimide substrate was patterned with platinum microelectrodes in addition to epoxy and dry film insulations to produce amperometric, enzyme-based sensors.…”

Highly Sensitive Electrochemical Glutamate Microsensors for Food Analysis

“…We fabricated a disposable multi-sensor platform in a cost-effective hybrid of thin-film and laminate technology ( Figure 1). Chip fabrication, including electrode modification and deposition of a Ag/AgCl on-chip reference electrode, was done on a wafer-level as described previously [4,5]. For sensor integration, glutamate oxidase was stably immobilized on platinum thin-film electrodes by chemical crosslinking into a protein matrix (Figure 1).…”