Within the field of energy conversion and storage, the single-atom catalyst (SAC) emerged as an effective catalyst for accelerating luminol-dissolved oxygen electrochemiluminescence (ECL) by catalyzing oxygen reduction reactions (ORR). Fe-N/P-C SACs, heteroatom-doped catalysts, were synthesized in this work to catalyze cathodic luminol electrochemiluminescence. P-doping may lower the energy barrier for the reduction of OH*, resulting in increased catalytic efficiency for oxygen reduction reactions. The consequence of oxygen reduction reaction (ORR) was the formation of reactive oxygen species (ROS) leading to the initiation of cathodic luminol ECL. Fe-N/P-C's superior ORR catalytic activity, compared to Fe-N-C, was demonstrated by the greatly enhanced ECL emission, catalyzed by SACs. Because the system's operation was critically tied to oxygen availability, a highly sensitive detection protocol for the typical antioxidant ascorbic acid yielded a detection limit of 0.003 nM. Rational modification of SACs using heteroatom doping, as detailed in this study, provides the possibility for a substantial improvement in ECL platform performance.
In plasmon-enhanced luminescence (PEL), a photophysical process, luminescent components experience a pronounced enhancement in luminescence due to their interaction with metal nanostructures. PEL's applications in designing robust biosensing platforms for luminescence-based detection and diagnostics, and in the creation of efficient bioimaging platforms, leverage its multiple advantages. These platforms achieve high-contrast, non-invasive, real-time optical imaging of biological tissues, cells, and organelles with high precision in spatial and temporal resolution. This review summarizes the recent strides in the development of PEL-based biosensors and bioimaging platforms, encompassing a broad spectrum of biological and biomedical applications. We meticulously examined rationally engineered PEL-based biosensors, which effectively detect biomarkers (proteins and nucleic acids) during point-of-care testing. The integration of PEL notably boosted the sensing capability. This paper examines the benefits and drawbacks of recently designed PEL-based biosensors, including those situated on substrates and in solutions, and further explores the integration of such PEL-based biosensing platforms within microfluidic devices, a promising avenue for multi-modal detection. In this review, comprehensive details about the recent innovations in the development of PEL-based multifunctional (passive targeting, active targeting, and stimuli-responsive) bioimaging probes are presented. The review also highlights the path forward for enhancing the design of robust PEL-based nanosystems to optimize diagnostic and therapeutic insights, especially in the context of imaging-guided therapy.
This paper details the development of a novel ZnO/CdSe semiconductor composite-based photoelectrochemical (PEC) immunosensor for the highly sensitive and quantitative measurement of neuron-specific enolase (NSE). The electrode's surface is protected from non-specific protein adsorption by a composite antifouling layer consisting of polyacrylic acid (PAA) and polyethylene glycol (PEG). Ascorbic acid (AA), functioning as an electron donor, clears photogenerated holes, thus improving the stability and intensity of the photocurrent. Quantitative detection of NSE is facilitated by the specific recognition process of antigen and antibody. The PEC antifouling immunosensor, incorporating ZnO/CdSe, demonstrates a significant linear range of 0.10 pg/mL to 100 ng/mL, combined with a low limit of detection of 34 fg/mL, opening up possibilities for clinical applications in the diagnosis of small cell lung cancer.
Digital microfluidics (DMF), a versatile lab-on-a-chip platform, enables integration with numerous sensor and detection technologies, including the utilization of colorimetric sensors. A novel approach, presented here, integrates DMF chips into a mini studio. A 3D-printed holder, pre-equipped with UV-LEDs, is used to initiate sample degradation on the chip before the complete analytical procedure, comprising reagent mixture, colorimetric reaction, and detection via an embedded webcam. The integrated system's capability was validated as a proof of concept through the indirect assessment of S-nitrosocysteine (CySNO) present in biological samples. For photolytic cleavage of CySNO, using UV-LEDs, nitrite and subsequent products were generated immediately on the DMF chip. Employing a modified Griess reaction, nitrite was detected colorimetrically, the reagents for which were generated through programmed droplet movement on DMF-based microfluidic devices. Optimized assembly and experimental parameters yielded a satisfactory correlation between the proposed integration and the results generated by a desktop scanner. immune sensing of nucleic acids Ninety-six percent of the CySNO was degraded to nitrite under the most suitable experimental setup. The analytical parameters underpinned the proposed method's linear performance for CySNO concentrations ranging between 125 and 400 mol L-1, signifying a limit of detection at 28 mol L-1. The analysis of both synthetic serum and human plasma samples, conducted successfully, demonstrated a statistical equivalence to spectrophotometric results at the 95% confidence level. This reinforces the great potential of the DMF and mini studio integration for a comprehensive analysis of low-molecular-weight compounds.
Exosomes, as a non-invasive biomarker, exhibit a crucial role in both breast cancer screening procedures and prognostic evaluations. However, crafting a straightforward, precise, and reliable approach to analyzing exosomes is still an obstacle. To analyze breast cancer exosomes, a one-step multiplex electrochemical aptasensor was created, relying on a multi-probe recognition strategy. As model targets, exosomes from the HER2-positive breast cancer cell line SK-BR-3 were chosen, and for capture, aptamers against CD63, HER2, and EpCAM were used. The gold nanoparticles (Au NPs) were decorated with a methylene blue (MB) modified HER2 aptamer and a ferrocene (Fc) modified EpCAM aptamer. MB-HER2-Au NPs and Fc-EpCAM-Au NPs were the signal units used. Selleckchem 3-MA Upon the addition of the mixture of target exosomes, MB-HER2-Au NPs, and Fc-EpCAM-Au NPs to the CD63 aptamer-modified gold electrode, two gold nanoparticles (one modified with MB and one with Fc) were specifically bound to the electrode surface. The binding was due to the recognition of the target exosomes by the three aptamers. Exosome one-step multiplex analysis was achieved through the detection of two distinct electrochemical signals. HNF3 hepatocyte nuclear factor 3 Not only does this strategy allow for the identification of breast cancer exosomes from other exosomes, including normal and other tumor-derived exosomes, but it also enables the separation of HER2-positive from HER2-negative breast cancer exosomes. Beyond that, its sensitivity was exceptional, detecting SK-BR-3 exosomes in a concentration as low as 34,000 particles per milliliter. Remarkably, this method proves applicable to the analysis of exosomes within complicated samples, an anticipated improvement for breast cancer screening and prognosis.
A superwettable microdot array fluorescence system was developed for the simultaneous, yet distinct, determination of Fe3+ and Cu2+ in red wine samples. Using polyacrylic acid (PAA) and hexadecyltrimethoxysilane (HDS), a wettable micropores array of high density was initially designed. The array was then further processed using the sodium hydroxide etching technique. To produce a fluoremetric microdot array platform, zinc metal-organic frameworks (Zn-MOFs) were fashioned as fluorescent probes and fixed within a micropores array. Exposure to Fe3+ and/or Cu2+ ions resulted in a substantial decrease in the fluorescence intensity of Zn-MOFs probes, enabling simultaneous analysis. Still, specific reactions concerning Fe3+ ions would likely occur when using histidine for the chelation of Cu2+ ions. The superwetting Zn-MOFs-based microdot array facilitates the accumulation of targeted ions from complex samples, eliminating the need for any pre-processing steps. Analysis of multiple samples is facilitated by minimizing cross-contamination of sample droplets from differing sources. Afterwards, a demonstration of the feasibility for simultaneous and separate determination of Fe3+ and Cu2+ ions in red wine examples was provided. The deployment of a microdot array-based detection platform presents promising avenues for the analysis of Fe3+ and/or Cu2+ ions, with potential applications spanning food safety, environmental monitoring, and medical diagnostics.
Black communities' reluctance to receive COVID vaccines is a serious issue, compounded by the profound racial inequities exposed by the pandemic's impact. Earlier research efforts have examined the public understanding of COVID-19 vaccines, including a dedicated look at the views within the Black community. Black individuals who have persistent COVID-19 symptoms may have a differing susceptibility to future COVID-19 vaccinations in comparison to those who haven't. Whether COVID vaccination mitigates or exacerbates long COVID symptoms is a matter of ongoing debate, as some studies suggest a potential positive outcome, while others find no significant impact or report a negative development. This study sought to characterize the factors contributing to perspectives on COVID-19 vaccines among Black adults with long COVID, in order to inform the development of future vaccine-related strategies and policy adjustments.
Fifteen adults experiencing lingering physical or mental health symptoms lasting a month or longer after acute COVID-19 infection were the subjects of semi-structured, race-concordant interviews conducted via Zoom. The interviews, after being transcribed and anonymized, underwent inductive thematic analysis to reveal factors affecting COVID vaccine perceptions and vaccine decision-making.
Five distinct themes were identified regarding public perception of vaccines: (1) Vaccine safety and efficacy; (2) Social implications of vaccine choices; (3) Navigating vaccine information; (4) Concerns of potential misuse by the government and scientific community; and (5) The impact of Long COVID.