An Amperometric Biosensor Based on a Bilayer of Electrodeposited Graphene Oxide and Co-Crosslinked Tyrosinase for L-Dopa Detection in Untreated Human Plasma.
Giuseppa CembaloRosanna CirielloCarmen TesoroAntonio GuerrieriGiuliana BiancoFilomena LelarioMaria Assunta AcquaviaAngela Di CapuaPublished in: Molecules (Basel, Switzerland) (2023)
L-Dopa, a bioactive compound naturally occurring in some Leguminosae plants, is the most effective symptomatic drug treatment for Parkinson's disease. During disease progression, fluctuations in L-DOPA plasma levels occur, causing motor complications. Sensing devices capable of rapidly monitoring drug levels would allow adjusting L-Dopa dosing, improving therapeutic outcomes. A novel amperometric biosensor for L-Dopa detection is described, based on tyrosinase co-crosslinked onto a graphene oxide layer produced through electrodeposition. Careful optimization of the enzyme immobilization procedure permitted to improve the long-term stability while substantially shortening and simplifying the biosensor fabrication. The effectiveness of the immobilization protocol combined with the enhanced performances of electrodeposited graphene oxide allowed to achieve high sensitivity, wide linear range, and a detection limit of 0.84 μM, suitable for L-Dopa detection within its therapeutic window. Interference from endogenous compounds, tested at concentrations levels typically found in drug-treated patients, was not significant. Ascorbic acid exhibited a tyrosinase inhibitory behavior and was therefore rejected from the enzymatic layer by casting an outer Nafion membrane. The proposed device was applied for L-Dopa detection in human plasma, showing good recoveries.
Keyphrases
- label free
- loop mediated isothermal amplification
- real time pcr
- randomized controlled trial
- gold nanoparticles
- end stage renal disease
- chronic kidney disease
- hydrogen peroxide
- type diabetes
- risk factors
- drug induced
- adipose tissue
- nitric oxide
- reduced graphene oxide
- prognostic factors
- insulin resistance
- peritoneal dialysis
- skeletal muscle
- electronic health record
- magnetic nanoparticles
- smoking cessation