Bioinspired N-C coated ZnO based electrochemiluminescence sensor for dopamine screening from neuroblastoma patient

Machine-Learning-Assisted Synthesis of Bimetallic Metal-Organic Frameworks for the Optimized Oxygen Evolution Reaction

Although a wide range of bimetallic metal-organic frameworks (MOFs) have been reported as electrocatalysts for the oxygen evolution reaction (OER), there is still a need for precise tuning of the metal precursors and composite ratios to minimize the overpotential and design highly efficient electrocatalysts. To achieve this, we applied machine learning (ML) algorithms to optimize the metal precursor and composite ratios, identifying the key factors that govern the OER performance. We first synthesized a bimetallic FeCo squarate-based MOF (FeCo-Sq MOF) using a solvothermal method and then optimized the metal precursor ratios using ML algorithms to achieve a low overpotential. To further enhance the OER efficacy, the ML-optimized FeCo-Sq MOF was coated with S-doped graphitic carbon nitride (SCN) and wrapped with polydopamine (PDA). The PDA wrapping not only increased the number of binding/adsorption sites for -OH but also enhanced the stability, charge/electron transfer kinetics, and effective anchoring of SCN on the MOF surface. To obtain optimal OER catalysts, the SCN loading was further fine-tuned through ML. The ML-optimized PDA-SCN@FeCo-Sq MOF exhibited high electrocatalytic performance, achieving a low overpotential of 310 mV and a Tafel slope of 56 mV/dec at a current density of 10 mA cm-2 in 1 M KOH. This study presents a promising ML-assisted strategy for designing high-performance PDA-SCN@FeCo-Sq MOF electrocatalysts for efficient water splitting.

Electrochemical luminescence sensor for the detection of Allure Red: double luminescence cooperative amplification strategy of self-supporting material Zn3Cu2O2 and CdTe@MWNTs

The self-supporting material Zn3Cu2O2 was synthesized through the methods of electrospinning combined with high-temperature calcination. A novel sensitive electrochemiluminescence (ECL) sensor based on Zn3Cu2O2 and CdTe@MWNTs was constructed by the multi-step amplification strategy. First, Zn3Cu2O2 and CdTe served as the ECL groups to construct the sensor, yielding a larger signal of the sensor in the presence of the co-reactant K2S2O8. Multi-walled carbon nanotubes (MWNTs) were introduced as a carrier to increase the signal value of the sensor further. The synergistic action of CdTe@MWNTs and Zn3Cu2O2 made the system obtain the maximum initial signal. With the addition of Allure Red (AR), the ECL signal decreased. The quenching phenomenon was not only due to the large organic molecule AR occupying the active sites of Zn3Cu2O2 and CdTe, but also, more importantly, because the sensor existed as an ECL-RET mechanism between CdTe and AR. The response mechanism and experimental conditions of the system were also investigated. Under optimal conditions, the sensor showed a linear relationship between the ECL signal change and the logarithm of AR concentration in the range 1.0 × 10-14 to 1.0 × 10-6 mol L-1, the linear equation was ∆I = 15,295.54 + 956.42 log CAR, and the correlation coefficient was 0.9928. The lowest detection limit of (S/N = 3) was 1.67 × 10-15 mol L-1. Satisfactory results were obtained for the analysis  of beverages.

Non-enzymatic electrochemical sensing of dopamine from COVID-19 quarantine person

The worldwide outbreak of COVID-19 pandemic, is not only a great threat to the victim life but it is leaving invisible devastating negative affect on mental health of quarantined individual because of isolation, depression, bereavement, and loss of income. Therefore, the precise monitoring catecholamine neurotransmitters specifically of dopamine (DA) is of great importance to assess the mental health. Thus, herein we have synthesized Co-based zeolitic imidazolate framework (ZIF-67) through solvothermal method for precise monitoring of DA. To facilitate the fast transportation of ions, highly conductive polymer, poly(3,4-ethylenedioxythiophene; PEDOT) has been integrated on the surface of ZIF-67 which not only provides the smooth pathway for ions/electrons transportation but also saves the electrode from pulverization. The fabricated ZIF-67/PEDOT electrode shows a significant sensing performance towards DA detection in terms of short diffusion pathways by expositing more active sites, over good linear range (15-240 μM) and a low detection limit of (0.04 μM) even in the coexistence of the potentially interfering molecules. The developed ZIF-67/PEDOT sensor was successfully employed for sensitive and selective monitoring of DA from COVID-19 quarantined person blood, thus suggesting reliability of the developed electrode.

Melamine-derived N-rich C-entrapped Au nanoparticles for sensitive and selective monitoring of dopamine in blood samples

Several neurological disorders, including Parkinson's disease, schizophrenia, human immunodeficiency virus infection, and restless leg syndrome, majorly result from disruption in the dopamine (DA) level. Thus, useful information about the treatment and prevention of various genetic majorly mental health problems can be obtained through precise and real-time monitoring of DA. Herein, we report the fabrication of novel N-rich carbon-coated Au nanoparticles (NC@Au-NPs) by deriving from melamine-crosslinked citrate-stabilized Au NPs. NC@Au-NPs offer fast electro-oxidation efficacy towards DA, because of strong electrostatic attraction between negatively charged NC@Au-NPs and positively charged DA. The catalytic efficacy and shelf life of the designed system were further boosted by applying a mixture of polydopamine (PDA) and benzimidazolium-1-acetate ionic liquid (IL) as a sandwich between the working electrode surface (graphitic pencil electrode: GPE) and the designed nanohybrid NC@Au-NPs as a redox mediator. The results indicate that the designed novel NC@Au/PDA-IL/GPE exhibits excellent sensitivity, selectivity, and reproducibility over a wide linear range (50-1000 nm) and a low detection limit of 0.002 μM ± 0.001 as well. The developed sensor was successfully applied to monitor DA in the blood of COVID-19 quarantined patients and pharmaceutical samples with high accuracy, thus suggesting a powerful tool for the diagnosis of mental problems.