Sandwich-structured nanoparticles-grafted functionalized graphene based 3D nanocomposites for high-performance biosensors to detect ascorbic acid biomolecule

Abstract

We present a highly sensitive and selective nano-biosensor for rapid, stable and highly reproducible detection of ascorbic acid (AA) in the presence of dopamine, uric acid and other interferences by a three-layer sandwich arrangement of nitrogen-doped functionalized graphene (NFG), silver nanoparticles (AgNPs) and nanostructured polyaniline (PANI) nanocomposite. The enhanced AA electrochemical properties of the NFG/AgNPs/PANI electrode is attributed to the superior conductivity of the NFG-PANI and the excellent catalytic activity of AgNPs. The critical modification of the AgNPs-grafted NFG-PANI coated on very low-cost fluorine doped tin oxide electrode (FTOE) increased the charge transfer conductivity of the electrode (the resistance drops down from 11,000 Ω to 6 Ω). The nano-biosensor was used to accurately detect AA in vitamin C tablets with the recovery of 98%. The sensor demonstrated a low detection limit of 8 µM (S/N = 3) with a very wide linear detection range of 10–11,460 µM, good reproducibility and excellent selectivity performance for AA detection. The results demonstrate that this nanocomposite is a promising candidate for rapid and selective detection of AA in practical clinical samples.

Reproducible and Scalable Generation of Multilayer Nanocomposite Constructs for Ultrasensitive Nanobiosensing

“…The progressive decreases in the impedance (from 1800 to 30 Ω) due to the deposition of the nanomaterials stems from the synergic effect of each component in the nanocomposite. NDG was cast coated on the CSPE as a substrate and then AgNPs were sandwiched between the NDG and PANI using dual potential chronoamperometry to increase binding and improve the conductivity of the electrode . We previously demonstrated that the significant increase in conductivity and surface area of the electrode as a result of nanocomposite coating significantly escalated the sensitivity of the electrode and vastly enhanced the biosensors' limit of detection compared to unmodified sensors reported earlier .…”

“…To do so, it was measured by recording the electrochemical signal (Δ j ) from bare CPSE, NDG, NDG/Ag, PANI, NDG/PANI, and NDG/Ag/PANI when exposed to 5 × 10 4 cells mL −1 SK‐BR3 cancer cells (Figure S7, Supporting Information). The importance of the sequence of each of these layers on biosensing performance of the functionalized electrodes has been studied elsewhere . With electrochemical signals in the range of −56 to −32 Δ j /µA cm −2 , CPSE, NDG, and NDG/Ag could not create a strong binding with immobilized cells.…”

“…To overcome these shortcomings, vast numbers of materials and functionalization protocols incorporated nanomaterials and polymers have been employed. These materials increased the surface area, conductivity, and resulted in the creation of ultrasensitive “nanofunctionalized sensors” or briefly “nanosensors.” Nanosensors are not only sensitive in detecting biomarkers at low concentrations but they can also identify the change of concentration in the matrices for various applications. This allowed quantitative screening of recovery from traumatic brain injuries and concussions, monitoring of cancer progression or regression in response to therapeutics, rapid detection of blood infection and sepsis, and managing the performance of treatments such as water and food treatment strategies .…”

“…This allowed quantitative screening of recovery from traumatic brain injuries and concussions, monitoring of cancer progression or regression in response to therapeutics, rapid detection of blood infection and sepsis, and managing the performance of treatments such as water and food treatment strategies . In addition, for enhancing the stability of the composite in complex biofluids or harsh environments, conductive nanocomposites with a large surface area have been combined with different nanoparticles to achieve sandwich constructs …”

Single-Step Modified Electrodes for Vitamin C Monitoring in Sweat

“…On the other side, nonenzymatic sensors make use of new materials to overcome the limitations of biological receptors in terms of cost and stability (Gnana Kumar et al, 2017). Several attempts have pursued this approach for ascorbic acid detection, for example using carbon-supported PdNi nanoparticles (NPs) on glassy carbon electrodes (Zhang et al, 2013), carbon nanoplatelets derived from ground cherry husks (Li et al, 2017) or silver NPs grafted graphene/polyaniline nanocomposites (Salahandish et al, 2019). Metal oxide NPs provide a high surface area and good electron transport kinetics (George et al, 2018), which also make them a good candidate for the development of nonenzymatic sensors.…”