Performance comparison with different methods for ethanol/O2 biofuel cell based on NAD+ cofactor immobilized and activated by two types of carbon nanoparticles

Small but Mighty: A Microfluidic Biofuel Cell-Based Biosensor for the Determination of Ethanol

We developed a membraneless-microfluidic biofuel cell (MBFC) for the quantification of ethanol. The system employs anolyte and catholyte solutions, each containing a biocatalyst and redox mediator. The laminar flow conditions in the microfluidic chip minimize the mixing between anolyte and catholyte and obviate the need for a membrane to separate them. When ethanol is added to the anolyte, alcohol dehydrogenase (ADH) catalyzes its oxidation to acetaldehyde, releasing electrons to the anode. On the cathode, electrons are transferred to horseradish peroxidase (HRP), which reduces hydrogen peroxide in the catholyte to water. We optimized key design factors and operating conditions. We also studied the incorporation of glycerol as a viscosity modifier, which improved the power and current density supplied by the MBFC, with a maximum power output of 307 µW cm-2 and an open circuit voltage of 0.733 V. The proposed ethanol/hydrogen peroxide MBFC was successfully applied as a biofuel cell-based sensor for the quantification of ethanol in a commercial liquor.

Nanostructured supports for multienzyme co-immobilization for biotechnological applications: Achievements, challenges and prospects

The synergistic combination of current biotechnological and nanotechnological research has turned to multienzyme co-immobilization as a promising concept to design biocatalysis engineering. It has also intensified the development and deployment of multipurpose biocatalysts, for instance, multienzyme co-immobilized constructs, via biocatalysis/protein engineering to scale-up and fulfil the ever-increasing industrial demands. Considering the characteristic features of both the loaded multienzymes and nanostructure carriers, i.e., selectivity, specificity, stability, resistivity, induce activity, reaction efficacy, multi-usability, high catalytic turnover, optimal yield, ease in recovery, and cost-effectiveness, multienzyme-based green biocatalysts have become a powerful norm in biocatalysis/protein engineering sectors. In this context, the current state-of-the-art in enzyme engineering with a synergistic combination of nanotechnology, at large, and nanomaterials, in particular, are significantly contributing and providing robust tools to engineer and/or tailor enzymes to fulfil the growing catalytic and contemporary industrial needs. Considering the above critics and unique structural, physicochemical, and functional attributes, herein, we spotlight important aspects spanning across prospective nano-carriers for multienzyme co-immobilization. Further, this work comprehensively discuss the current advances in deploying multienzyme-based cascade reactions in numerous sectors, including environmental remediation and protection, drug delivery systems (DDS), biofuel cells development and energy production, bio-electroanalytical devices (biosensors), therapeutical, nutraceutical, cosmeceutical, and pharmaceutical oriented applications. In conclusion, the continuous developments in nano-assembling the multienzyme loaded co-immobilized nanostructure carriers would be a unique way that could act as a core of modern biotechnological research.

Noni fruit extract ameliorates alcohol-induced hangover symptoms by reducing the concentrations of alcohol and acetaldehyde in a Sprague Dawley rat model and a human intervention study

Various studies have reported that Noni shows various health effects. This study aimed to assess the ability of Noni fruit extract to serve as a single active functional ingredient for the alleviation of hangover symptoms in Sprague Dawley rats and healthy subjects in a single-dose, randomized, double-blind, crossover, placebo-controlled study. The rats were orally administered Noni fruit extract at 50 or 100 mg per kg body weight (B.W.) and HOVENIA. The blood ethanol (EtOH) and acetaldehyde concentrations were significantly lower in the 100 mg per kg B.W. group than in the EtOH group. Alcohol dehydrogenase and aldehyde dehydrogenase activity tended to increase in the 100 mg kg^-1 B.W. group. In the human study, 30 subjects received either a placebo or Noni fruit extract (1 g). The Noni fruit extract group showed significantly faster time point at which the maximum concentration (T_max) of alcohol than in the placebo group. In addition, blood acetaldehyde levels and diarrhea at 40 and 720 min after alcohol intake and the area under the curve between 40 and 60 min of acetaldehyde were significantly decreased in the Noni fruit extract group compared to the placebo group. According to the QUalitative INteraction Trees, subjects who were ≤36 years old who consumed more alcohol (>15 drinks per week) and had a higher total hangover score (>27.5 and 33) presented significantly lower blood acetaldehyde levels and less severe hangover symptoms. These results indicate that Noni fruit extract has the potential to improve hangover symptoms by decreasing alcohol and acetaldehyde levels.

Nanomaterials in bioelectrochemical devices: on applications enhancing their positive effect

Electrochemical biosensors and biofuel cells are finding an ever-increasing practical application due to several advantages. Biosensors are miniature measuring devices, which can be used for on-the-spot analyses, with small assay times and sample volumes. Biofuel cells have dual benefits of environmental cleanup and electric energy generation. Application of nanomaterials in biosensor and biofuel-cell devices increases their functioning efficiency and expands spheres of use. This review discusses the potential of nanomaterials in improving the basic parameters of bioelectrochemical systems, including the sensitivity increase, detection lower-limit decrease, detection-range change, lifetime increase, substrate-specificity control. In most cases, the consideration of the role of nanomaterials links a certain type of nanomaterial with its effect on the bioelectrochemical device upon the whole. The review aims at assessing the effects of nanomaterials on particular analytical parameters of a biosensor/biofuel-cell bioelectrochemical device.