Accelerating the development of implantable neurochemical biosensors by using existing clinically applied depth electrodes.
Alexander R MacdonaldFrancessca CharltonDamion K CorriganPublished in: Analytical and bioanalytical chemistry (2022)
In this study, an implantable stereo-electroencephalography (sEEG) depth electrode was functionalised with an enzyme coating for enzyme-based biosensing of glucose and L-glutamate. This was done because personalised medicine could benefit from active real-time neurochemical monitoring on small spatial and temporal scales to further understand and treat neurological disorders. To achieve this, the sEEG depth electrode was characterised using cyclic voltammetry (CV), differential pulse voltammetry (DPV), square wave voltammetry (SWV), and electrochemical impedance spectroscopy (EIS) using several electrochemical redox mediators (potassium ferri/ferrocyanide, ruthenium hexamine chloride, and dopamine). To improve performance, the Pt sensors on the sEEG depth electrode were coated with platinum black and a crosslinked gelatin-enzyme film to enable enzymatic biosensing. This characterisation work showed that producing a useable electrode with a good electrochemical response showing the expected behaviour for a platinum electrode was possible. Coating with Pt black improved the sensitivity to H 2 O 2 over unmodified electrodes and approached that of well-defined Pt macro disc electrodes. Measured current showed good dependence on concentration, and the calibration curves report good sensitivity of 29.65 nA/cm 2 /μM for glucose and 8.05 nA/cm 2 /μM for L-glutamate with a stable, repeatable, and linear response. These findings demonstrate that existing clinical electrode devices can be adapted for combined electrochemical and electrophysiological measurement in patients and obviate the need to develop new electrodes when existing clinically approved devices and the associated knowledge can be reused. This accelerates the time to use and application of in vivo and wearable biosensing for diagnosis, treatment, and personalised medicine.
Keyphrases
- carbon nanotubes
- solid state
- label free
- gold nanoparticles
- reduced graphene oxide
- optical coherence tomography
- ionic liquid
- molecularly imprinted
- healthcare
- newly diagnosed
- blood glucose
- high resolution
- single molecule
- uric acid
- blood pressure
- combination therapy
- adipose tissue
- patient reported outcomes
- magnetic resonance
- blood brain barrier
- nitric oxide
- tissue engineering
- solid phase extraction
- drug administration
- neural network