A Carbon-Based Antifouling Nano-Biosensing Interface for Label-Free POCT of HbA1c

Abstract

Electrochemical biosensing relies on electron transport on electrode surfaces. However, electrode inactivation and biofouling caused by a complex biological sample severely decrease the efficiency of electron transfer and the specificity of biosensing. Here, we designed a three-dimensional antifouling nano-biosensing interface to improve the efficiency of electron transfer by a layer of bovine serum albumin (BSA) and multi-walled carbon nanotubes (MWCNTs) cross-linked with glutaraldehyde (GA). The electrochemical properties of the BSA/MWCNTs/GA layer were investigated using both cyclic voltammetry and electrochemical impedance to demonstrate its high-efficiency antifouling nano-biosensing interface. The BSA/MWCNTs/GA layer kept 92% of the original signal in 1% BSA and 88% of that in unprocessed human serum after a 1-month exposure, respectively. Importantly, we functionalized the BSA/MWCNTs/GA layer with HbA1c antibody (anti-HbA1c) and 3-aminophenylboronic acid (APBA) for sensitive detection of glycated hemoglobin A (HbA1c). The label-free direct electrocatalytic oxidation of HbA1c was investigated by cyclic voltammetry (CV). The linear dynamic range of 2 to 15% of blood glycated hemoglobin A (HbA1c) in non-glycated hemoglobin (HbAo) was determined. The detection limit was 0.4%. This high degree of differentiation would facilitate a label-free POCT detection of HbA1c.

Enabling Multiplexed Electrochemical Detection of Biomarkers with High Sensitivity in Complex Biological Samples

“…We anticipate more iterations of the biosensor that will incorporate other transduction systems, such as transistors, as well as novel biological counterparts to antibodies (e.g., aptamers, affimers, molecularly imprinted polymers) to develop even more advanced real-time biosensing in the future . In fact, others have used our coating with screen-printed carbon electrodes to detect blood glycated hemoglobin A with a LOD of 8 μM …”

“…1 Recently, our method was adapted by others to develop a carbon-based antifouling nanocomposite where BSA and multiwalled carbon nanotubes (MWCNTs) were cross-linked with GA and similar antifouling properties were observed. 46 Upon application of an electrical potential, metal nanoparticles can oxidize interfering molecules present in blood (e.g., uric acid, dopamine, tryptophan) leading to an electrochemical background signal. 47,48 We overcame this potential limitation by replacing the AuNW with amine-terminated rGOx nanoflakes, which also significantly reduced the cost of the nanocomposite.…”

“…64 In fact, others have used our coating with screen-printed carbon electrodes to detect blood glycated hemoglobin A with a LOD of 8 μM. 46 There are many areas where the utility of our coating can be extended further. For instance, label-free sensing is gaining more attention because eliminating labels can simplify designs and reduce both assay steps and cost.…”

“…BSA/AuNW/GA preserved 93% of the original signal when analysis was carried out in a 1% BSA solution, and 88% of the signal was retained in unprocessed serum or plasma after 1 month of exposure . Recently, our method was adapted by others to develop a carbon-based antifouling nanocomposite where BSA and multiwalled carbon nanotubes (MWCNTs) were cross-linked with GA and similar antifouling properties were observed …”

Carbon Dots: Classification, Properties, Synthesis, Characterization, and Applications in Health Care—An Updated Review (2018–2021)

“…Carbon based nanomaterials usually encompass fullerenes (C 60 ) [32], graphene (GR) [33], carbon black (CB) [34], carbon nanohorns (CNHs) [35], carbon nanodiamonds [36], carbon nanofibers (CNFs) [37], carbon nanotubes (CNTs) such as single-walled carbon nanotubes (SWCNTs) [38] and multi-walled carbon nanotubes (MWCNTs) [39], as well as quantum dots (QDs) such as carbon dots (CDs) [40]. All these carbon nanomaterials exhibit unique and unparalleled features that result in their huge exploitation for a variety of sensing applications such as disease diagnosis, metal ion detection, food and environmental regulations, etc.…”