ScFv-modified graphene-coated IDE-arrays for ‘label-free’ screening of cardiovascular disease biomarkers in physiological saline

Abstract

Fatty-acid binding proteins (FABP) and myeloperoxidases (MPO) are associated with many chronic conditions in humans and considered to be important biomarkers for diagnosis of cardiac diseases. Here we assemble a new electrical biosensor platform based on graphene-coated interdigitated electrode arrays (IDE-arrays) towards ultrafast, label-free screening of heart type-FABP and MPO. Arrays of nanoscale (nanoIDE) and microscale (microIDE) electrode-arrays were fabricated on wafer-scale by combining nanoimprint and photolithography processes. Chemical vapor deposition grown multilayer graphene was transferred onto nano/microIDE-arrays and used as a high surface-to-volume ratio electrical transducer. Novel biofunctional layers of specially engineered anti-h-FABP and anti-MPO single-chain fragment variables (scFv) were immobilized onto graphene-coated IDE-array sensor platform for electrical detection of h-FABP and MPO in physiological saline. scFv fragments show increased sensitivity in comparison to the state-of-the-art competitive ELISA for their higher affinity towards target analytes. Deploying FABP and MPO specific scFvs as receptor molecules onto our high-sensitivity graphene-coated IDE-arrays with identical sensor characteristics and assays covering clinically relevant concentrations in physiological saline, we demonstrate realization of a simple and versatile biosensor platform capable of high performance cardiac-bioassays for point-of-care applications.

Recent Progress of Biomarker Detection Sensors

“…Singh et al fabricated an anti-CEA/PBSE/graphene/Cu biomarker detection platform for CEA detection based on electrochemical impedance spectroscopy (EIS) technique [ 35 ]. Delle et al transferred multilayer graphene, as a high surface-to-volume ratio electrical layer, onto interdigitated electrode arrays to improve electrical conductivity, which is shown in Figure 3(b) [ 27 ]. Aydın et al decorated the ITO electrode with composite material (carbon black and PGMA polymer) for anti-IL-8 antibody immobilization and then fabricated a high-sensitivity label-free biosensor for IL-8 detection [ 36 ].…”

“…(a) 2D material GO and aptamer modified on the GCE, reproduced from Yang et al [ 26 ]. (b) Graphene-based 2D material modified chip by wetting transfer, reproduced from Delle et al [ 27 ], and (c) rGO and nanocomposites Pd, Au, and Pt immobilized on the electrode, reproduced from Barman et al [ 28 ] with their permissions.…”

Machine Learning Approach to Enhance the Performance of MNP-Labeled Lateral Flow Immunoassay

“…The accuracy can indicate systematic errors in a system and was calculated by comparing the concentrations measured with different spiking concentrations. The system accuracy was tested by detecting five concentrations (1,10,50,200, and 500 mIU mL −1 ) of HCG standard solutions (with three strips for each concentration), where each strip was inserted into the reader 10 times and the average value and standard deviation were calculated for each concentration. System accuracy was evaluated by calculating recovery as the ratio of the average detected concentration and standard concentration.…”

Bioelectronics and Interfaces Using Monolayer Graphene

“…For this purpose, it is necessary to functionalize the graphene surface with appropriate receptors, which are antibodies in most cases. Alternate receptors such as antibody fragments and aptamers have also been utilized for protein detection . The detection of the binding of analyte on to the functionalized graphene surface is carried out in many cases using field‐effect.…”