Emerging Trends in Non-Enzymatic Cholesterol Biosensors: Challenges and Advancements

The development of a highly sensitive and selective non-enzymatic electrochemical biosensor for precise and accurate determination of multiple disease biomarkers has always been challenging and demanding. The synthesis of novel materials has provided opportunities to fabricate dependable biosensors. In this perspective, we have presented and discussed recent challenges and technological advancements in the development of non-enzymatic cholesterol electrochemical biosensors and recent research trends in the utilization of functional nanomaterials. This review gives an insight into the electrochemically active nanomaterials having potential applications in cholesterol biosensing, including metal/metal oxide, mesoporous metal sulfide, conductive polymers, and carbon materials. Moreover, we have discussed the current strategies for the design of electrode material and key challenges for the construction of an efficient cholesterol biosensor. In addition, we have also described the current issues related to sensitivity and selectivity in cholesterol biosensing.

A facile construction of Ag/MoSe2 composite based non-enzymatic amperometric sensor for hydrogen peroxide

We report an electrochemical non-enzymatic method for hydrogen peroxide (H2O2) detection based on Ag nanoparticle-decorated MoSe2 (Ag/MoSe2-500) hybrid nanostructures. These hybrid nanocomposites are easily prepared by in-situ reduction of Ag+...

Ni and Co synergy in bimetallic nanowires for the electrochemical detection of hydrogen peroxide

The development of a highly sensitive and selective non-enzymatic electrode catalyst for the detection of a target molecule was remained a great challenge. In this regard, bimetallic nanowires (BMNWs) are considered as promising electrode material for their fascinating physical/chemical properties superior to a single system. In this article, nickel cobalt (Ni _x -Co) BMNWs with tunable stoichiometry were prepared by a template assisted electrodeposition method and their catalytic performance was investigated for the detection of hydrogen peroxide (H₂O₂). It has been found that Ni-Co (0.5:1) BMNWs/PC electrode exhibits superior non-enzymatic sensing ability toward H₂O₂ detection with a high selectivity. The electrode shows fast response within ∼3 s and an excellent reproducible sensitivity of 2211.4 μAmM^-1 cm^-2, which is the best compared to the individual Ni, Co, Ni-Co (0.3:1) BMNWs and previously reported electrodes. In addition, the electrode shows a linear response in the wide concentration range from 0.005 mM to 9 mM, low detection limit of 0.5 μM (S/N = 3.2) and a relatively long-term storage (50 d). Moreover, the sensor reveals excellent results for H₂O₂ detection in the real samples. The enhanced sensitivity of the Ni-Co (0.5:1) BMNWs based electrode may be due to the stable structure and synergy of Ni and Co. The results demonstrate that the catalytic activity of the electrode binary catalyst towards H₂O₂ detection can be improved by adjusting the Ni/Co ratio in BMNWs. The excellent performance of the electrode suggests that Ni-Co BMNWs are promising candidate for the construction of cost-effective electrochemical sensors for medical and industrial applications.

Synthesis of Fe3O4/Ag nanohybrid ferrofluids and their applications as antimicrobial and antifibrotic agents

To date, the search for creating stable ferrofluids with excellent properties for biomedical application is one of the challenging scientific and practical investigations. In this study, novel Fe3O4/Ag nanohybrid ferrofluids from iron sand were synthesized using a double-layer method. The Fe3O4/Ag nanocomposites exhibited stable crystallite sizes of 11.8 12.1 nm and 36.8-37.2 nm for Fe3O4 and Ag, respectively. The lattice parameters of the spinel structure Fe3O4 and face-centered cubic Ag were respectively 8.344 Å and 4.091 Å. With increasing Ag amount, the crystallite phase of Ag in the nanocomposites increased from 40.2% to 77.2%. The XPS results confirmed that Fe3O4/Ag nanocomposites were successfully prepared, where Fe3O4 mixed well with Ag via strong ionic bonding. The FTIR results confirmed the presence of Fe3O4/Ag, oleic acid, and dimethyl sulfoxide as the filler, first layer, and second layer, respectively. The as-prepared ferrofluids exhibited superparamagnetic behavior, where the saturation magnetization decreased with increasing Ag content. The Fe3O4/Ag nanohybrid ferrofluids exhibited excellent antimicrobial performance against Bacillus subtilis, Staphylococcus aureus, Escherichia coli, and Candida albicans. More importantly, the Fe3O4/Ag nanohybrid ferrofluids decreased the progression of liver fibrosis-related inflammation and fibrogenic activity on hepatic stellate cells.