Hierarchical CNTs@CuMn Layered Double Hydroxide Nanohybrid with Enhanced Electrochemical Performance in H₂S Detection from Live Cells

Abstract

The precise monitoring of H2S has aroused immense research interest in the biological and biomedical fields since it is exposed as a third endogenous gasotransmitter. Hence, there is an urgent requisite to explore an ultrasensitive and economical H2S detection system. Herein, we report a simple strategy to configure an extremely sensitive electrochemical sensor with a 2D nanosheet-shaped layered double hydroxide (LDH) wrapped carbon nanotubes (CNTs) nanohybrid (CNTs@LDH), where a series of CNTs@CuMn-LDH nanohybrids with varied amounts of LDH nanosheets grafted on a conductive CNTs backbone has been synthesized via a facile coprecipitation approach. Taking advantage of the unique core–shell structure, the integrated electrochemically active CuMn-LDH nanosheets on the conductive CNTs scaffold, the maximum interfacial collaboration, and the superior specific surface area with a plethora of surface active sites and ultrathin LDH layers, the as-prepared CNTs@CuMn-LDH nanoarchitectures have exhibited superb electrocatalytic activity toward H2S oxidation. Under the optimum conditions, the electrochemical sensor based on the CNTs@CuMn-LDH nanohybrid shows remarkable sensing performances for H2S determination in terms of a wide linear range and a low detection limit of 0.3 nM (S/N = 3), high selectivity, reproducibility, and durability. With marvelous efficiency achieved, the proposed sensing platform has been practically used in in situ detection of abiotic H2S efflux produced by sulfate reducing bacteria and real-time in vitro tracking of H2S concentrations from live cells after being excreted by a stimulator which in turn might serve as early diseases diagnosis. Thus, our core–shell hybrid nanoarchitectures fabricated via structural integration strategy will open new horizons in material synthesis, biosensing systems, and clinical chemistry.

Layered Double Hydroxides: A Toolbox for Chemistry and Biology

“…Recently, dopamine biosensors for real time detection of dopamine (detection limit down to 2 nM) from live cells (human neuronal functioning neuroblastoma cell line SH-SY 5Y) were realized in the form of composite materials produced by exfoliated charged nanosheets of LDHs and graphene [179]. Similarly, carbon nanotubes loaded onto a CuMn LDH nanohybrid allowed for a high-sensitivity electrochemical detection of H 2 S from live A375 cells (detection limit equal to 0.3 nM) [180].…”

Electrochemical immunosensor development based on core-shell high-crystalline graphitic carbon nitride@carbon dots and Cd0.5Zn0.5S/d-Ti3C2Tx MXene composite for heart-type fatty acid–binding protein detection

“…With the strong binding between these biomolecules, immunosensors show high selectivity and very high sensitivity, making them attractive for many applications in different fields of science [10]. Especially, the replacement of simple electrochemical techniques with conventional methods has gained substantial attention due to the efficient operation feature and less chemical consumption [7][8][9][11][12][13][14][15][16][17][18]. For example, an amperometric immunosensor for h-FABP detection was presented based on screen-printed carbon electrode and this amperometric immunosensor showed a linearity range from 4.0 to 250.0 ng mL −1 with a LOD of 4.0 ng mL −1 [19].…”

The role of biosensors in coronavirus disease-2019 outbreak

“…The technology that exists behind the testing is biosensing platforms that apply the strategy of bio-recognition elements or binding target molecules in a particular way for the detection of biological analytes [ 6 , 7 ]. This type of binding acts as transducers which create measurable signals either directly through impedance measurements, surface plasmon resonance, or labeling the molecules such as enzymes/optical compounds [ 8 , 9 ]. In this review, we have summarized the biosensor based technologies which are able to detect SARS-CoV-2 effectively.…”