Covalent enzyme immobilization by poly(ethylene glycol) diglycidyl ether (PEGDE) for microelectrode biosensor preparation

In vivo continuous and simultaneous monitoring of brain energy substrates with a multiplex amperometric enzyme-based biosensor device

“…Most of the brain glucose levels detected by biosensors refer to the striatum and to values between 0.3 and 0.7 mM (Ahmad et al, 2008;Fillenz and Lowry, 1998;Kiyatkin and Lenoir, 2012;Leegsma-Vogt et al, 2003;Lowry et al, 1998a). A recent study performed in anesthetized animals with a biosensor implanted in the mPFC describes basal levels of 0.68 mM (Vasylieva et al, 2011), which is roughly half of what we report (1.30 7 0.14 mM). However, in the mentioned study, basal levels were calculated based on pre-calibration data, using less sensitive (12.3 73.8 pA/mM) biosensors.…”

“…A recent study, employing biosensors, showed that insulin administration did not influence glucose levels in the striatum (Ahmad et al, 2008). However, a similar decrease in glucose mPFC levels as presently reported in response to insulin (25 U/kg) administration has been noted (Vasylieva et al, 2011).…”

“…These type of biosensors were successfully applied for in vivo biomonitoring of neurotransmitters (Mitchell, 2004;Oldenziel et al, 2006;Pomerleau et al, 2003;Wahono et al, 2012) and energy biomarkers (Ahmad et al, 2008;Calia et al, 2009;Gramsbergen et al, 2004;Leegsma-Vogt et al, 2003;Lowry et al, 1998b;Roche et al, 2011;Vasylieva et al, 2011). Simultaneous monitoring of glucose and lactate has already been successfully described, even coupled to a telemetric device (Rocchitta et al, 2013).…”

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

“…Immobilization resulted either in complete enzyme deactivation or insufficient fixation. Thus, in our hands poly (ethylene glycol) diglycidyl ether (PEGDE) appeared more suitable for lactate oxidase fixation (Vasylieva et al, 2011). Sensitive and stable biosensors were obtained using solution containing 20 mg/mL of lactate oxidase, 20 mg/mL of BSA and 80 mg/mL of PEGDE in PBS buffer (10 mM, pH 7.4).…”

Multisite monitoring of choline using biosensor microprobe arrays in combination with CMOS circuitry

“…Many of these sensors are based on insulated Pt wires or carbon fibers that are exposed at the tip to create a disc or cylinder microelectrode [19,24,27,28,31,35,38]. Enzyme coating is either performed by dip coating [19,24,27] or by dispensing small amounts of enzyme solution over the active electrode area [31,38].…”