Electrochemical impedimetric analysis of different dimensional (0D–2D) carbon nanomaterials for effective biosensing of L-tyrosine

Abstract

Electrochemical biosensors employing nano-transduction surfaces are considered highly sensitive to the morphology of nanomaterials. Various interfacial parameters namely charge transfer resistance, double layer capacitance, heterogeneous electron transfer rate and diffusion limited processes, depend strongly on the nanostructure geometry which eventually affects the biosensor performance. The present work deals with a comparative study of electrochemical impedance-based detection of L-tyrosine (or simply tyrosine) by employing carbon nanostructures (graphene quantum dots, single walled carbon nanotubes (CNTs) and graphene) along with tyrosinase as the bio-receptor. Specifically, the role of carbon nanostructures (i.e. 0D, 1D and 2D) on charge transfer resistance is investigated by applying time-varying electric field at the nano-bioelectrode followed by calculating the heterogeneous electron transfer rate, double layer capacitor current and their effects on limits of detection and sensitivities towards tyrosine recognition. A theoretical model based on Randel’s equivalent circuit is proposed to account for the redox kinetics at various carbon nanostructure/enzyme hybrid surfaces. It was observed that, the 1D morphology (single walled CNTs) exhibited lowest charge transfer resistance ∼2.62 kΩ (lowest detection limit of 0.61 nM) and highest electron transfer rate ∼0.35 μm s−1 (highest sensitivity 0.37 kΩ nM−1 mm−2). Our results suggest that a suitable morphology of carbon nanostructure would be essential for efficient and sensitive detection of tyrosine.

Enhancing Electrochemical Signal for Efficient Chiral Recognition by Encapsulating C60 Fullerene into Chiral Lanthanum-Based MOFs

“…It can be seen the peak current ratio for the detection of Trp enantiomers gradually increased with the increase of drop-coating volume and drop-coating concentration at the beginning, but gradually decreased when the drop-coating volume was larger than 10 μL and the drop-coating concentration was larger than 10 mg. mL –1 . The reason may be that a smaller number of chiral MOFs provides fewer chiral sites, while excessive chiral MOF deposition results in high charge transfer and diffusion resistance, which affects chiral recognition performance …”

“…The reason may be that a smaller number of chiral MOFs provides fewer chiral sites, while excessive chiral MOF deposition results in high charge transfer and diffusion resistance, which affects chiral recognition performance. 32 To further investigate the anti-interference ability of the chiral electrochemical platform of C 60 @L/D-[La(BTB)] n / GCE, we also studied the effects of some organic small molecules (salicylic acid, tetracycline, glycolic acid, and dopamine) and inorganic metal ions (Cu 2+ , Fe 2+ , Zn 2+ , Na + , and K + ) on the chiral recognition ability of C 60 @L/D-[La(BTB)] n /GCE electrochemical sensing interfaces. The effect of organic small molecules on the chiral recognition performance of C 60 @L/D-[La(BTB)] n /GCE are shown in Figure 5e,f and g,h, which show that there is little effect on the recognition ability of the chiral interface in the presence of organic small molecules.…”

A Novel Electroanalytical Biosensor Based on ZIF‐8/Acetylcholinesterase Bio‐nanohybrids for Early Management of Hirschsprung Disease

“…The application of time‐varying electric field yields highly specific information regarding bulk and interfacial processes, owing to the unique behavior of electrodes, electrolyte and electron transfer phenomena at different frequency ranges – a feature which is not accessible in voltammetric techniques [44]. The distinction between real and imaginary components allows us to effectively model the electrode‐electrolyte setup using a simple equivalent electrical circuit (Randel's circuit), for studying heterogenous electron transfer kinetics; which eventually helps us understand various basic interfacial parameters (Randel's circuit elements) that are in play during heterogenous charge transfer process.…”

“…The distinction between real and imaginary components allows us to effectively model the electrode‐electrolyte setup using a simple equivalent electrical circuit (Randel's circuit), for studying heterogenous electron transfer kinetics; which eventually helps us understand various basic interfacial parameters (Randel's circuit elements) that are in play during heterogenous charge transfer process. Such a technique eventually allows us to better visualize the redox process or binding phenomena involved [44]. In the present case, insights onto the interfacial electron transfer kinetics, during acetylcholine detection, was performed by curve fitting of Nyquist spectra obtained from EIS within 0.1 Hz–0.1 MHz at sinusoidal amplitude of 100 mV.…”

Biosensing Efficiency of Nanocarbon-Reinforced Polyacrylonitrile Nanofibrous Matrices

“…Such a comparison between graphene and SWCNTs in detection of L-tyrosine was recently reported. 52 The results are intended to provide an assessment of the different systems towards tailoring NF matrices for optimal performance in biosensors. The filler content for each type of nanocarbon was optimized to reach a satisfactory compromise between NF morphology and biosensor performance.…”