ZnO Nanowire Arrays on 3D Hierachical Graphene Foam: Biomarker Detection of Parkinson’s Disease

Abstract

We report that vertically aligned ZnO nanowire arrays (ZnO NWAs) were fabricated on 3D graphene foam (GF) and used to selectively detect uric acid (UA), dopamine (DA), and ascorbic acid (AA) by a differential pulse voltammetry method. The optimized ZnO NWA/GF electrode provided a high surface area and high selectivity with a detection limit of 1 nM for UA and DA. The high selectivity in the oxidation potential was explained by the gap difference between the lowest unoccupied and highest occupied molecular orbitals of a biomolecule for a set of given electrodes. This method was further used to detect UA levels in the serum of patients with Parkinson's disease (PD). The UA level was 25% lower in PD patients than in healthy individuals. This finding strongly implies that UA can be used as a biomarker for PD.

Optical biosensors based on ZnO nanostructures: advantages and perspectives. A review

“…Nowadays, the most developed and used biosensor platforms are electrical [29,32,33,37,42,46,47,56,87] and electrochemical [16,30,31,38,39,55,88,90,[92][93][94]. Electrical in particular are based on their Field Effect Transistor (FET) platforms demonstrate high level of detection but require additional input of lithography and nanotechnology, what makes these devices more complex and expensive.…”

“…Regarding to a progress in nanotechnology and material science, new technological methods have been developed to fabricate nanostructured ZnO templates with high surface area and advanced properties for biosensors. Nanostructured ZnO films have been widely used as template in electrochemical biosensors before demonstrating good sensitivity and low detection limit [30,39,55,88,90,[92][93][94], while ZnO nanowires, nanorods etc. have been widely used recently as the sensing element in FET biosensors [29,33,87].…”

ZnO nanostructures in enzyme biosensors

“…ZnO nanocomposites containing these nanomaterials have also been applied in biosensors [11,13,14,[66][67][68][69][70][71][72][73][74][75][76]. Graphene/ ZnO NPs hybrids (Fig.…”

Nanotechnology platforms in Parkinson’s Disease

“…In another study by Yue and colleagues, zinc oxide (ZnO) nanowire arrays (each nanowire being sub-100 nm in diameter and a couple of microns in height) were prepared upon a three dimensional foam made of graphene and the assembly could selectively detect dopamine along with urate and ascorbate by a method called differential pulse voltammetry. The addition of nanowires lead to high electrical conductivity and enhancement of sensitivity of electrochemical biosensors leading to reduction in the detection limit to 1 nanomolar for dopamine and uric acid in the serum of PD patients [61]. The field testing of this array lead to the interesting finding of a reduced UA level in 7 PD patients than in healthy individuals which can make uric acid a potential biomarker in the diagnosis of PD [61].…”

“…The addition of nanowires lead to high electrical conductivity and enhancement of sensitivity of electrochemical biosensors leading to reduction in the detection limit to 1 nanomolar for dopamine and uric acid in the serum of PD patients [61]. The field testing of this array lead to the interesting finding of a reduced UA level in 7 PD patients than in healthy individuals which can make uric acid a potential biomarker in the diagnosis of PD [61]. In yet another modification, Kurzatkowska et al developed ion-channel mimetic self-assembled monolayers of macrocyclic polyamines deposited onto gold electrodes for electrochemical determination of dopamine [62].…”