All-in-one calcium nanoflowers for dual outputs biosensor: A simultaneous strategy for depression drug evaluation and non-invasive stress assessment.

Although enzyme-based signal amplification has been well developed for biosensors, their application in low-abundance biomarker under complicated conditions detection remains challenge. Cortisol is a steroid hormone and a quantitative evaluation of cortisol can objectively assess stress and depression. However, various factors can induce slight cortisol changes in body fluids, and this in turn sets a strict requirement for bedside testing of cortisol for evaluation of stress. Herein, all-in-one calcium nanoflowers (CaHPO4-AM-HRP-SA NFs) integrated with horseradish peroxidase (HRP), α-amylase (α-AM), and streptavidin (SA) have been synthesized to develop a simple but powerful biosensor for cortisol detection. High specific surface area and allosteric modulator provided by the hybrid nanoflowers as inherent advantages significantly boosted the catalytical ability and stability compared with the free enzymes. CaHPO4-AM-HRP-SA NFs also endowed the sensor with two output signals of one sample, leading the as-prepared sensor to realize self-calibration detection. Aside from using a traditional microplate reader to measure the signal, it could also be read out by a handheld blood glucose meter and a mobile phone. The sensor exhibited attractive simplicity and sensitivity with a low LOD of 98.5 pg mL-1. It accomplished the sensitive evaluation of cortisol in rat serum and assessed the antidepressant effects of different medications. The non-invasive and reliable cortisol detection is also achieved in human urine and saliva samples. Overall, we have demonstrated that the sensor can be deployed as a promising platform to evaluate drug efficiency and monitor stress in a simple and non-invasive manner.

Multifunctional amino acids empowering bifunctional biosensing platform for depression study.

Poor availability of objective approaches hinders effective diagnosis and treatment for depression. Biosensors provide a promising platform for the development of quantitative and practical methods for disease detection, as well as for drug discovery. Here, we developed an electrochemical biosensor has been established with the ability to simply and accurately detect the trace glucocorticoid receptor alpha (GRα), as a key biomarker of depression, in both hippocampus and blood cells. The integration of amino-ion graphene oxide (IL-rGO) and amino acid-coated gold nanoparticles (AA-AuNPs) via green synthesis remarkably magnifies the electrochemical signals, where amino acids play multiple roles as reducing agents, stabilizers, and bridging agents. After the optimization among AA-AuNPs@IL-rGO nanocomposites based on five typical amino acids, a biosensing surface has been constructed to implement analysis in real samples as a bifunctional platform. The obtained biosensor exhibited a remarkably low limit of detection (0.283 pg mL-1) and could thus sensitively identify the GRα differences in healthy and depressive rats with and without fluoxetine. The electrochemical biosensor developed herein was not only outstandingly sensitive but also simple to use and labor-saving, making it a promising all-in-one platform for depression diagnosis and drug discovery.

A systematic bibliometric review of clean energy transition: Implications for low-carbon development.

More voices are calling for a quicker transition towards clean energy. The exploration and exploitation of clean energy such as wind energy and solar energy are effective means to optimise energy structure and improve energy efficiency. To provide in-depth understanding of clean energy transition, this paper utilises a combination of multiple bibliometric mapping techniques, including HistCite, CiteSpace and R Bibliometrix, to conduct a systematic review on 2,191 clean energy related articles obtained from Web of Science (WoS). We identify five current main research streams in the clean energy field, including Energy Transition, Clean Energy and Carbon Emission Policy, Impact of Oil Price on Alternative Energy Stocks, Clean Energy and Economics, and Venture Capital Investments in Clean Energy. Clearly, the effectiveness of policy-driven and market-driven energy transition is an important ongoing debate. Emerging research topics are also discussed and classified into six areas: Clean Energy Conversion Technology and Biomass Energy Utilisation, Optimisation of Energy Generation Technology, Policy-Making in Clean Energy Transition, Impact of Clean Energy Use and Economic Development on Carbon Emissions, Household Use of Clean Energy, and Clean Energy Stock Markets. Accordingly, more and more research attention has been paid to how to improve energy efficiency through advanced clean energy technology, and how to make targeted policies for clean energy transition and energy market development. This article moves beyond the traditional literature review methods and delineates a systematic research agenda for clean energy research, providing research directions for achieving low-carbon development through the clean energy transition.

Electrochemical sensor based on magnetic nanohybrids of multiple phthalocyanine doped ferrites/CMWCNTs for detection of rosmarinic acid.

Ferrites have attracted considerable attention in biosensor developments owing to their favorable electrochemical and magnetic properties. Speedy and trace analysis can be succeeded by the sensors based on magnetic nanohybrids. In this work, we reported a novel method for one-step synthesis of magnetic ferrites composed of Fe and phthalocyanine. After hybridization with carbonylated multi wall carbon nanotubes, a sensor based on Fe3O4-Pc-CMWCNTs nanocomposites was fabricated for the detection of rosmarinic acid (RA), a bioactive phytochemical. The sensor can be constructed within 30s without any complicated process. A comparison of electrochemical activity between ZnFe2O4-Pc-CMWCNTs and Fe3O4-Pc-CMWCNTs nanohybrids also has been accomplished in this work. Compared with ZnFe2O4-Pc-CMWCNTs based on commonly used ferrites, Fe3O4-Pc-CMWCNTs/MGCE exhibited a higher catalytical ability for the detection of RA. The sensor modified with Fe3O4-Pc-CMWCNTs displayed a low LOD of 0.182 µM with a wide linear range from 0.2 to 400 µM, which was 30 times more sensitive than the one based on ZnFe2O4-Pc-CMWCNTs. The obtained sensor also owned an excellent selectivity, reproducibility, repeatability, and stability, which made it achieve the measurements in plant sample and human serum.

A novel oriented immunosensor based on AuNPs-thionine-CMWCNTs and staphylococcal protein A for interleukin-6 analysis in complicated biological samples.

Interleukin-6 (IL-6) is of high importance for disease diagnosis and prognosis in human health since it's a crucial component in immune homeostasis, hematopoiesis, and metabolism. Herein, an immunosensor has been developed for monitoring IL-6, which is fabricated by Au nanoparticles (Au NPs)-thionine (THI)-carboxylated multi walled carbon nanotubes (CMWCNTs) as the substrate with high conductivity. Staphylococcal protein A (SPA) could directionally capture antibody to reduce steric hindrance caused by random immobilization. Built upon the high efficiency of IL-6 antibody immobilization by the SPA on the sensing surface, the immunosensor exhibited a favorable activity for IL-6 detection. Under optimal conditions, the biosensor presented a LOD of 2.87 pg mL-1 and a wide linear range from 0.01 ng mL-1 to 800 ng mL-1 in serum samples. Furthermore, the assembled sensor successfully quantified the IL-6 concentration in serum and different tissue lapping liquids (lung, heart, liver) from rats with myocardial infarction. The satisfactory performance of the proposed sensor not only broadens its application in clinical monitoring of IL-6 but also provides a novel approach to study inflammation in rats.

An Ultrasensitive Non-Enzymatic Sensor for Quantitation of Anti-Cancer Substance Chicoric Acid Based on Bimetallic Nanoalloy with Polyetherimide-Capped Reduced Graphene Oxide.

Exploiting effective therapies to fight tumor growth is an important part of modern cancer research. The anti-cancer activities of many plant-derived substances are well known, in part because the substances are often extensively distributed. Chicoric acid, a phenolic compound widely distributed in many plants, has drawn widespread attention in recent years because of its extraordinary anti-cancer activities. However, traditional methods for quantifying chicoric acid are inefficient and time-consuming. In this study, an ultrasensitive non-enzymatic sensor for the determination of chicoric acid was developed based on the use of an Au@Pt-polyetherimide-reduced graphene oxide (PEI-RGO) nanohybrid-modified glassy carbon electrode. Owing to the considerable conductivity of PEI-functionalized RGO and the efficient electrocatalytic activity of Au@Pt nanoalloys, the designed sensor exhibited a high capacity for chicoric acid measurement, with a low detection limit of 4.8 nM (signal-to-noise ratio of 3) and a broad linear range of four orders of magnitude. With the advantages provided by the synergistic effects of Au@Pt nanocomposites and PEI-RGO, the developed sensor also revealed exceptional electrochemical characteristics, including superior sensitivity, fast response, acceptable long-term stability, and favorable selectivity. This work provides a powerful new platform for the highly accurate measurement of chicoric acid quantities, facilitating further research into its potential as a cancer treatment.

A Non-Enzymatic Sensor Based on Trimetallic Nanoalloy with Poly (Diallyldimethylammonium Chloride)-Capped Reduced Graphene Oxide for Dynamic Monitoring Hydrogen Peroxide Production by Cancerous Cells.

Catching cancer at an early stage is necessary to make it easier to treat and to save people's lives rather than just extending them. Reactive oxygen species (ROS) have sparked a huge interest owing to their vital role in various biological processes, especially in tumorigenesis, thus leading to the potential of ROS as prognostic biomarkers for cancer. Herein, a non-enzymatic biosensor for the dynamic monitoring of intracellular hydrogen peroxide (H2O2), the most important ROS, via an effective electrode composed of poly (diallyldimethylammonium chloride) (PDDA)-capped reduced graphene oxide (RGO) nanosheets with high loading trimetallic AuPtAg nanoalloy, is proposed. The designed biosensor was able to measure H2O2 released from different cancerous cells promptly and precisely owing to the impressive conductivity of RGO and PDDA and the excellent synergistic effect of the ternary alloy in boosting the electrocatalytic activity. Built upon the peroxidase-like activity of the nanoalloy, the developed sensor exhibited distinguished electrochemical performance, resulting in a low detection limit of 1.2 nM and a wide linear range from 0.05 µM to 5.5 mM. Our approach offers a significant contribution toward the further elucidation of the role of ROS in carcinogenesis and the effective screening of cancer at an early stage.