Buried-Gate MWCNT FET-Based Nanobiosensing Device for Real-Time Detection of CRP

Abstract

C-reactive protein (CRP), an acute-phase protein synthesized in the liver in response to inflammation, is one of the biomarkers used for the detection of several diseases. Sepsis and cardiovascular diseases are two of the most important diseases for which detection of CRP at very early stages in the clinical range can help avert serious consequences. Here, a CNT-based nanobiosensing system, which is portable and reproducible, is used for label-free, online detection of CRP. The system consists of an aptameric CNT-based field-effect transistor benefiting from a buried gate geometry with Al 2 O 3 as a high dielectric layer and can reflect the pro-cytokine concentration. Test results show that the device responds to CRP changes within 8 min, with a limit of detection as low as 150 pM (0.017 mg L –1 ). The device was found to have a linear behavior in the range of 0.43–42.86 nM (0.05–5 mg L –1 ). The selectivity of the device was tested with TNF-α, IL-6, and BSA, to which the nanosensing system showed no significant response compared with CRP. The device showed good stability for 14 days and was completely reproducible during this period. These findings indicate that the proposed portable system is a potential candidate for CRP measurements in the clinical range.

Rapid and Easy Detection of Microcystin-LR Using a Bioactivated Multi-Walled Carbon Nanotube-Based Field-Effect Transistor Sensor

“…The left shift of the Dirac point from −0.17 V to −0.22 V implied that more electrons were doped into MWCNTs when MC-LR, which is weakly and negatively charged at pH 7.2, was bonded to the MC-TA aptamer. The working principle of this FET can be explained by charge transfer from either the MC-LR or MC-LR-MCTA aptamer and not by the electrostatic gating effect [23,38,42,[44][45][46][47]. Consistent with other observations [48,49], the n-characteristic region is less defined probably because of the adsorption of oxygen in the solution.…”

“…Notably, the Dirac point, positioned at −0.17 V to the FET in pure PBS buffer, shifted to a more negative value (−0.22 V) in the MC-LR-spiked PBS solution (≥0.1 ng/mL). The fabricated MCTA-MWCNT FET is an n-doped p-type FET [37][38][39][40][41][42][43][44][45]. The left shift of the Dirac point from −0.17 V to −0.22 V implied that more electrons were doped into MWCNTs when MC-LR, which is weakly and negatively charged at pH 7.2, was bonded to the MC-TA aptamer.…”

Electrochemical Aptasensor for Selective and Sensitive Detection of Staphylococcus aureus Using Graphene oxide/poly Deep Eutectic Solvent/Nickel Oxide Nanocomposite Modified Electrode

“…Among the diagnostic methods, electrochemical‐based biosensors have features that make them very efficient in designing and manufacturing biosensors. These features include low cost, simple operation, ease of signal translation, and convenient miniaturization [13–16] . Designing a suitable modified platform is the main challenge to improve the electrochemical biosensing technology that ultimate to effectively immobilize biorecognition elements and determination of the analyte [17] .…”

“…These features include low cost, simple operation, ease of signal translation, and convenient miniaturization. [13][14][15][16] Designing a suitable modified platform is the main challenge to improve the electrochemical biosensing technology that ultimate to effectively immobilize biorecognition elements and determination of the analyte. [17] Graphene has unique properties like mechanical, electrical, optical, and thermal that attracted attentions over the recent years.…”

Detection of C-Reactive Protein Using a Flexible Biosensor with Improved Bending Life

“…Many attempts have already been made to develop new CRP measurement methodologies. These methods are broadly categorized into five groups, 8,14 including field-effect transistors, 15,16 optical, 17 piezoresistive, microfluidic, impedimetric, 7,11,18 and electrochemical biosensors. 19,20 Among all these methods, electrochemical biosensors for point-of-care testing (POCT) applications offer several more advantages over other POCT methods.…”