NiCo-LDH Hollow Nanocage Oxygen Evolution Reaction Promotes Luminol Electrochemiluminescence.

Conventional luminol co-reactant electrochemiluminescence (ECL) systems suffer from low stability and accuracy due to factors such as the ease of decomposition of hydrogen peroxide and inefficient generation of reactive oxygen species (ROS) from dissolved oxygen. Inspired by the luminol ECL mechanism mediated by oxygen evolution reaction (OER), the nickel-cobalt layered double hydroxide (NiCo-LDH) hollow nanocages with hollow structure and defect state are used as co-reaction promoters to enhance the ECL emission from the luminol-H2 O system. Thanks to the hollow structure and defect state, NiCo-LDH hollow nanocages show excellent OER catalytic activity, which can stabilize and efficiently produce ROS and enhance the ECL emission. Additionally, mechanistic exploration suggests that the ROS involved in the co-reaction of the luminol-H2 O system are derived from the OER reaction process, and there is a positive correlation between ECL intensity and the OER catalytic activity of the co-reaction promoter. The selection of catalysts with excellent OER catalytic activity is a key factor in improving ECL emission. Finally, a dual-mode immunosensor is constructed for the detection and analysis of alpha-fetoprotein (AFP) based on the promoting effect of NiCo-LDH hollow nanocages on the luminol-H2 O ECL system.

Electrochemiluminescence Enhancement and Passivation Mitigation in Carbon Nitride Semiconductors via an Integrated Ternary Heterostructure Strategy.

In recent years, carbon nitride (CN) has attracted substantial attention in the field of electrochemiluminescence (ECL) applications, owing to its outstanding optical and electronic properties. However, the passivation of CN during the ECL process has contributed to reduced stability and poor repeatability. While some studies have tried to boost ECL performance by altering CN through doping and vacancies, effectively suppressing CN passivation at high potentials continues to be challenge. In this study, the built-in electric field and the Schottky barrier effect is used to expedite the transfer of electrons from CN to the molybdenum disulfide (MoS2) conduction band. This transfer deterred excessive electron injection into the CN band, thus mitigating its electrochemical degradation. Moreover, by introducing nickel nanoparticles (Ni NPs) as catalytic active sites, it is facilitated that the decomposition of potassium persulfate (K2S2O8), thereby enhancing both the stability and intensity of ECL emission. In the end, the application of ternary heterostructure as sensing platform for the cancer biomarker carcinoembryonic antigen (CEA) demonstrated high sensitivity. This research introduces a novel approach to overcome CN passivation, paving the way for more promising applications of CN in energy, environmental, and biosensing fields.

Engagement Along the PrEP Care Continuum Among Men Who Have Sex with Men in China: A Systematic Review and Meta-analysis.

Pre-exposure prophylaxis (PrEP), including daily oral, on-demand, and long-acting injectable (LAI), is a promising HIV prevention intervention for men who have sex with men (MSM). We conducted a systematic review on engagement with the PrEP continuum among MSM in China. A total of 756 studies were initially identified and 36 studies were included (N = 26,021). In the 20 studies (N = 13,886) examining PrEP awareness, 32.4% (95% CI: 25.1-40.7) of MSM were aware of PrEP. In the 25 studies (N = 18,587) examining willingness, 54.5% (95% CI: 41.9-66.5) MSM indicated they were willing to use PrEP. The pooled prevalence of PrEP uptake from 9 studies (N = 6,575) was 4.9% (95% CI: 1.4-15.8%), while pooled estimates of adequate adherence from five studies (N = 2,344) among MSM on PrEP was 40.7% (95% CI: 20.0-65.2%). Subgroup analyses suggested studies conducted after 2015 (versus before) tended to report higher awareness and uptake. Awareness was highest for daily oral PrEP, followed by on-demand, and LAI PrEP; willingness to use was highest for LAI PrEP. The operationalization of willingness and adherence constructs varied across studies and complicated the interpretation of pooled estimates. This review revealed gaps in the PrEP care continuum among MSM in China, with relatively low awareness and uptake (in contrast to willingness and adherence) as the major potential barriers to widespread implementation and the need for a unified approach to defining and measuring PrEP outcomes.

Dual-functional Nanomaterials Polyo-phenylenediamine and Ru-Au Complement Each Other to Construct an Electrochemical and Electrochemiluminescent Dual-Mode Aptamer Sensor for Sensitive Detection of Alternariol.

To sensitively monitor trace amounts of alternariol (AOH) in fruits, a dual-mode aptamer sensor utilizing the dual-function nanomaterial PoPD/Ru-Au was developed. This sensor provides both electrochemical (EC) and electrochemiluminescence (ECL) signals, which can greatly avoid the potential false positive of the traditional single signal, thus enhancing the accuracy and reliability of detection results. Polyo-phenylenediamine (PoPD), known for its favorable EC response, can also assist in enhancing the ECL behavior of Ru-Au. Furthermore, Ru-Au demonstrates excellent ECL performance and effectively activates K2S2O8 to amplify the EC response of PoPD. The complementary effect of the two can effectively amplify the final detection signal. Additionally, the PoPD/Ru-Au nanomaterial exhibits excellent electrical conductivity, further enhancing the EC and ECL response signals. The experimental results demonstrate that the EC detection range of AOH was 0.01-100 ng/mL, while the ECL detection range was 0.001-100 ng/mL, both exhibiting a satisfactory linear relationship. Therefore, the mutual verification of the detection results can be highly realized, and the purpose of avoiding wrong detection can be achieved.

Electrochemiluminescence Immunosensors Based on ECL-RET Triggering between Mn SANE/PEI-Luminol and PtCu/h-MPF for Ultrasensitive Detection of CEA.

In this paper, a novel donor-acceptor pair was creatively proposed based on the principle of electrochemiluminescence resonance energy transfer (ECL-RET): luminol immobilized on polyethyleneimine (PEI)-functionalized manganese-based single-atom nanozymes (Mn SANE/PEI-luminol, donor) and a PtCu-grafted hollow metal polydopamine framework (PtCu/h-MPF, acceptor). A quenched ECL immunosensor was constructed for the ultrasensitive analysis of carcinoembryonic antigen (CEA). Mn SANE, as an efficient novel coreaction accelerator with the outstanding performance of significantly activating H2O2 to produce large amounts of ROS, was further modified by the coreactant PEI, which efficiently immobilized luminol to form a self-enhanced emitter. As a result, the electron transport distance was effectively shortened, the energy loss was reduced, and luminol achieved a high ECL efficiency. More importantly, PtCu-grafted h-MPF (PtCu/h-MPF) was proposed as a novel quencher. The UV-vis spectra of PtCu/h-MPF partially overlap with the ECL spectra of Mn SANE/PEI-luminol, which can effectively trigger the ECL-RET behavior between the donor and the acceptor. The multiple quenching effect on Mn SANE/PEI-luminol was achieved, which significantly improved the sensitivity of the immunosensor. The prepared immunosensor exhibited good linearity in the concentration range of 10-5 to 80 ng/mL. The results indicate that this work provides a new method for the early detection of CEA in clinical diagnosis.

Construction of a Dual-Mode Immune Platform Based on the Photothermal Effect of AgCo@NC NPs for the Detection of α-Fetoprotein.

Compared with the accuracy of a single signal and the limitation of environmental applicability, the application value of dual-mode detection is gradually increasing. To this end, based on the photothermal effect of Ag/Co embedded N-rich mesoporous carbon nanomaterials (AgCo@NC NPs), we designed a dual-mode signal response system for the detection of α-fetoprotein (AFP). First, AgCo@NC NPs act as a photothermal immunoprobe that converts light energy into heat driven by a near-infrared (NIR) laser and obtains temperature changes corresponding to the analyte concentration on a hand-held thermal imager. In addition, this temperature recognition system can significantly improve the efficiency of Fenton-like reactions. AgCo@NC NPs act as peroxidase mimics to initiate the generation of poly N-isopropylacrylamide (PNIPAM, resistance enhancer) by cascade catalysis and the degradation of methylene blue (MB), thus enabling electrochemical testing. The dual-mode assay ranges from 0.01 to 100 and 0.001-10 ng/mL, with lower limits of detection (LOD) of 3.2 and 0.089 pg/mL, respectively, and combines visualization, portability, and high efficiency, opening new avenues for future clinical diagnostics and inhibitor studies.

Characterizing the Impact of the COVID-19 Pandemic on HIV PrEP care: A Review and Synthesis of the Literature.

The global COVID-19 pandemic and associated lockdown measures have caused disruptions to sexual health services and created additional barriers to the continuity of HIV pre-exposure prophylaxis (PrEP) among key populations. This review provides an examination of the influences of the pandemic on engagement in the PrEP care continuum. Using the PRISMA guideline, 46 studies were included in this review and the synthesis. Most of the studies were conducted in high-income settings through quantitative analysis. A majority of studies examining the changes in PrEP use suggested a decline or discontinuation in PrEP uptake during the pandemic. The most common reasons for stopping using PrEP were perceived barriers to PrEP-related care, having reduced sexual behaviors and fewer sexual partners, and reduced perceived risk of HIV infection. Limited studies documenting an increase in PrEP uptake were all in specific PrEP optimizing programs. During the pandemic, there is also an emerging trend of switching to on-demand PrEP from daily oral PrEP. Future studies should understand the mechanism of strategies that facilitated the improvements during the pandemic. PrEP implementation programs should consider alternative PrEP modalities and provide consistent and comprehensive knowledge about correct information.

Changes in high-risk sexual behavior, HIV and other STI testing, and PrEP use during the COVID-19 pandemic in a longitudinal cohort of adolescent men who have sex with men 13 to 18 years old in the United States.

The COVID-19 pandemic has disrupted sexual health services among those most vulnerable to HIV acquisition, such as adolescent men who have sex with men (AMSM). We sought to characterize the changes in sexual-risk behaviors, HIV and other STI testing, and pre-exposure prophylaxis (PrEP) use among a longitudinal cohort of AMSM aged 13 to 18 years before and during the COVID-19 pandemic. We observed a significant decline in HIV testing and a marginal decrease in other STI testing since the pandemic began in March 2020. Outreach efforts and innovative remote delivery of sexual health services are needed to support access to healthcare services among AMSM as the pandemic persists.

RESUMEN: La pandemia de COVID-19 ha afectado la prestación de servicios de salud sexual para los más vulnerables, tales como los hombres adolescentes que tienen relaciones sexuales con hombres (AMSM; por sus siglas en ingles). En una cohorte longitudinal de AMSM de 13 a 18 años, examinamos los cambios en comportamientos sexuales de alto riesgo, la prueba de VIH, las pruebas de otras enfermedades de transmisión sexual, y el uso de Profilaxis Preexposición (PrEP) para el VIH antes y durante la pandemia. Desde el inicio de la pandemia en marzo de 2020, observamos una disminución significativa en la frecuencia de pruebas de VIH y una disminución marginal en la frecuencia de pruebas de otras enfermedades de transmisión sexual. Mientras persista la pandemia, serán necesarios más esfuerzos de divulgación e innovaciones en la prestación remota de servicios de salud sexual para apoyar el acceso a dichos servicios por parte de AMSM.

The Effect of the Shikamana Peer-and-Provider Intervention on Depressive Symptoms, Alcohol Use, and Other Drug Use Among Gay, Bisexual, and Other Men Who Have Sex with Men in Kenya.

Kenyan gay, bisexual, and other men who have sex with men (GBMSM) face stigma and discrimination, which may adversely impact mental health and limit antiretroviral therapy (ART) adherence among GBMSM living with HIV. We evaluated whether the Shikamana peer-and-provider intervention, which improved ART adherence among participants in a small randomized trial, was associated with changes in mental health or substance use. The intervention was associated with a significant decrease in PHQ-9 score between baseline and month 6 (estimated change - 2.7, 95% CI - 5.2 to - 0.2, p = 0.037) compared to standard care. In an exploratory analysis, each one-point increment in baseline HIV stigma score was associated with a - 0.7 point (95% CI - 1.3 to - 0.04, p = 0.037) greater decrease in PHQ-9 score over the study period in the intervention group. Additional research is required to understand factors that influence this intervention's effects on mental health outcomes.

Depression as a mediator between intimate partner violence (IPV) and CD4 cell count among men who have sex with men (MSM) living with HIV in China.

Intimate partner violence (IPV) is associated with adverse mental and physical outcomes among men who have sex with men (MSM) living with HIV. Few studies focus on psychological IPV, such as verbal threats. This study examined the associations between different forms of IPV and depression and CD4+ cell count, with depression as a mediator for the association between IPV and CD4+ cell count. Data for these analyses were derived from a larger cross-sectional study on HIV-HCV co-infection among MSM in Shanghai, China (N = 1623). We estimated the average causal mediation effects (ACME) and average direct effects (ADE) through three steps. About 16% of participants experienced IPV, with forced sex (7%), verbal threats (5%), and thrown objects (4%) being most common. Verbal threats showed the strongest link with depression and low CD4+ cell count. Depression fully mediated the relationship between verbal abuse and low CD4+ cell count, suggesting it as a potential pathway between psychological IPV and poorer HIV-related health outcomes. More research on psychological IPV is warranted to examine its health impacts. Mental health could be a potential focus of intervention to enhance HIV-related health outcomes among MSM with IPV experience.

Mpox on Reddit: a Thematic Analysis of Online Posts on Mpox on a Social Media Platform among Key Populations.

The 2022-2023 mpox outbreak has disproportionately impacted gay, bisexual, and other men who have sex with men (GBMSM). The US CDC recommended individuals to explore safer sexual practices that minimize the potential risk of exposure and also strongly encouraged for eligible individuals to prioritize vaccination. This study aimed to analyze social media data related to mpox on Reddit since the mpox outbreak and identify themes associated with the impact on social behaviors and social processes among targeted population. Publicly available data were collected from the social media Reddit. We extracted the summarized mpox-related posts since the beginning of May 2022 from popular subreddits that were popular among GBMSM. We thematically analyzed the content to identify the overall themes related to the GBMSM's responses to the outbreak. There is an overall increase in the number of daily mpox-related posts, with three upticks in late May, late July, and early August 2022, which may correspond to the dates that the first mpox case was identified in the USA, the WHO declared a global public health emergency, and the US Department of Health and Human Services declared a public health emergency. Four themes were identified: (1) changes in sexual behaviors and social activities; (2) mpox vaccine attitude, uptake, and hesitancy; (3) perceived and experienced stigma and homophobia, and mental distress; and (4) online information-seeking and mutual aid and support. GBMSM changed their sexual behaviors and social activities to mitigate their exposure to the virus during this outbreak and actively sought and shared information about mpox vaccination in their respective settings, while some were hesitant due to concerns about side effects and potential effectiveness. Perceived and experienced stigma and discrimination on gay- and same sex-identify have impacted GBMSM's mental health. Interventions to promote the mpox vaccine must address the historical medical mistrust and vaccine hesitancy among GBMSM.

Prevalence of Nicotine and Tobacco Product Use by Sexual Identity, Gender Identity, and Sex Assigned at Birth Among Emerging Adult Tobacco Users in California, United States.

INTRODUCTION: Sexual and gender minority (SGM) nicotine and tobacco use disparities are well-documented among youth and young adults (YYA), and despite decades of prevention efforts, these disparities stubbornly persist. To better understand tobacco use disparities and craft tailored interventions, tobacco use patterns must be assessed in a contemporary sample of YYA across lines of sexual and gender identity, sex assigned at birth, and tobacco product types. AIMS AND METHODS: Data were from an online survey of a diverse sample of emerging adult tobacco users (ages 18-29; N = 1491) in California, United States (2020-2021). Participants were recruited from various online and in-person locations. Bivariate and adjusted models assessed differences in four nicotine and tobacco use outcomes (past 30-day use of cigarettes, e-cigarettes, other tobacco products, and multiple tobacco product types) across six groups: Cisgender heterosexual males, cisgender heterosexual females, cisgender sexual minority (SM) males, cisgender SM females, transfeminine participants, and transmasculine participants. RESULTS: Compared to cisgender heterosexual males, both transfeminine (OR = 2.25, 95% confidence intervals (CI) = 1.29 to 4.05) and transmasculine (OR = 1.85, 95% CI = 1.32 to 2.80) participants had higher odds of using cigarettes. Few differences were noted between groups in use of e-cigarettes. Cisgender heterosexual males had higher odds of other tobacco product use, compared to most other groups (eg, cisgender SM males: OR = 0.57, 95% CI = 0.37 to 0.87). Transmasculine participants had higher odds of multiple product use, compared to cisgender heterosexual females. Among multiple product users, transfeminine participants had the highest prevalence of using all three individual product types (35.6%). CONCLUSIONS: Results highlight the need for different tobacco control approaches across sexual and gender identities, sex assigned at birth, and nicotine and tobacco products. IMPLICATIONS: SGM nicotine and tobacco use disparities remain entrenched, despite concerted efforts to reduce them. The SGM population is heterogeneous and different SGM subgroups may have different needs. This study assessed, among young adult nicotine and tobacco users in California, U.S. patterns of tobacco use across sexual and gender identities, sex assigned at birth, as well as specific tobacco products used-a necessity to craft tailored tobacco control measures. We found patterns of nicotine and tobacco product use across several of these characteristics, highlighting how different prevention and cessation interventions may be needed to meaningfully address SGM nicotine and tobacco use disparities.

The associations between HIV stigma and mental health symptoms, life satisfaction, and quality of life among Black sexual minority men with HIV.

PURPOSE: With the advancement of antiretroviral therapy (ART), HIV/AIDS has become a manageable illness, similar to other chronic conditions. This study examined the associations between HIV stigma and patient-reported outcomes including mental health symptoms, life satisfaction, and quality of life among Black sexual minority men with HIV. METHODS: We analyzed baseline data from a randomized comparison trial of a mobile app intervention aimed to address the social work and legal needs of Black sexual minority men with HIV in Los Angeles County. We used validated scales including the Berger HIV stigma scale, the Patient Health Questionnaire-9 & the General Anxiety Disorder-7, the Satisfaction with Life Scale, and the Ladder Scale to assess HIV stigma, depressive symptoms, anxiety, life satisfaction, and quality of life, and we conducted multivariable linear regression to examine their associations. RESULTS: Participants experienced HIV stigma especially about disclosure concerns (e.g., 81.9% participants indicated "I am very careful who I tell that I have HIV") and public attitudes (52.3% believed "Most people with HIV are rejected when others find out"). In the multivariable models, higher overall stigma scores were associated with higher likelihood of experiencing depression (adjusted b = 0.235, p < 0.001) and anxiety (adjusted b = 0.188, p = 0.002), and lower life satisfaction (adjusted b = - 0.236, p < 0.001) and quality of life (adjusted b = - 0.053, p = 0.013), adjusting for clinical characteristics including ART initiation, viral load suppression, and medication adherence. In addition, being attacked or harassed in the past year were significantly associated with lower life satisfaction and quality of life (adjusted b = - 3.028, p = 0.046; adjusted b = - 1.438, p = 0.002). CONCLUSION: Our findings highlight the need for focused HIV stigma reduction interventions to promote the overall well-being of Black sexual minority men with HIV. Strategies to promote the patient-reported outcomes may benefit from trauma-informed approaches.

Social Determinants of Disease: HIV and COVID-19 Experiences.

PURPOSE OF REVIEW: The differential impact of the COVID-19 and HIV pandemics on marginalized communities has renewed calls for more robust and deeper investigation into structural and social causes of health inequities contributing to these infections, including underlying factors related to systematic racism. Using the Social Determinants of Health (SDOH) framework, we analyzed parallel and divergent factors associated with COVID-19 and HIV/AIDS and the prevalence of disparate disease in diverse communities. We utilized PRISMA guidelines to identify relevant literature (N = 210 articles) that resulted in a review of 125 articles included in our synthesis. RECENT FINDINGS: With racial health inequities as a core contributor to disease vulnerability, we also identified other factors such as economic stability, social and community support, the neighborhood and built environment, healthcare access and quality, and education access and quality as important socioecological considerations toward achieving health equity. Our review identifies structural and systematic factors that drive HIV and COVID-19 transmission. Our review highlights the importance of not solely focusing on biomedical interventions as solutions to ending HIV and COVID-19, but rather call for building a more just public health and social service safety net that meets the needs of people at the intersection of multiple vulnerabilities.

Patient-Reported Treatment Satisfaction and Quality of Life Among People Living with HIV Following the Introduction of Dolutegravir-Based ART Regimens in Ukraine.

In 2017, the government of Ukraine initiated its ART Optimization Initiative, revising its national antiretroviral therapy (ART) guidelines and embracing Dolutegravir (DTG) as a backbone of first-line ART regimens. A cross-sectional survey of 464 ART patients from 22 large ART clinics was carried out in mid-2019. The survey assessed patient-reported outcomes (PROS) including treatment satisfaction, physical health, mental health, depression, side effects of ART, and adherence. The associations between ART regimen and PROs were assessed using bivariable and multivariable generalized estimating equations (GEE) models. More than half (55.6%) of the patients were satisfied with their current ART regimen. Less than a half (45.3%) considered their physical health as good while only 36.9% rated their mental health as good, 21.3% reported moderate or severe depression, 82.3% reported no side effect in the past 4 weeks, and 44.4% reported not missing ART medication in the past month. In adjusted analysis, patients starting ART with DTG had higher treatment satisfaction compared to people continuing LPV-based regimens (aOR = 0.49, 95% confidence interval: 0.22-0.90). Also in adjusted analyses, unemployment, low income, and history of injection drug use were associated with unfavorable PROs. While the results indicate modestly favorable effects of ART Optimization, there is clearly a need for complementary interventions to improve PROs among disadvantaged ART patients in Ukraine.

PrEP Use and Persistence Among Young Sexual Minority Men 17-24 Years Old During the COVID-19 Pandemic.

The COVID-19 pandemic has caused disruptions to health care access for sexual and gender minorities in the U.S. We sought to explore the impact of COVID-19 on HIV pre-exposure prophylaxis (PrEP) use and sexual health services by assessing PrEP eligibility and use, changes in sexual behaviors, and HIV/STI testing during the COVID-19 pandemic. We surveyed 239 young sexual minority men (YSMM) 17-24 years old between April and September 2020 in the U.S. One-in-seven YSMM PrEP users discontinued use during the pandemic, and all those who discontinued PrEP reported a decrease in sexual activity. Twenty percent reported difficulty getting prescriptions and medications from their doctors or pharmacies, and more than 10% reported challenges accessing HIV/STI testing. Among those who met Centers for Disease Control and Prevention criteria for PrEP (n = 104), 86.5% were not currently using PrEP. Among those surveyed 3 months or later after the start of major COVID-19 stay-at-home measures (n = 165), 35.8% reported CAS with a causal partner within the past 3 months during the COVID-19 pandemic. Seeking HIV testing was associated with reporting condomless anal sex in the previous 3 months, indicating the necessity for ensuring continuity of basic sexual health services for YSMM. Failure to adequately adjust HIV prevention services and intervention in the face of pandemic-related adversity undermines efforts to end the HIV epidemic in the U.S.

RESUMEN: La pandemia de COVID-19 ha causado interrupciones en el acceso a la atención médica para las minorías sexuales y de género en los EE. UU. Buscamos explorar el impacto de COVID-19 en el uso de la profilaxis de preexposición al VIH (PrEP) y los servicios de salud sexual mediante la evaluación de la elegibilidad y el uso de PrEP, los cambios en los comportamientos sexuales y las pruebas de VIH/ITS durante la pandemia de COVID-19. Encuestamos a 239 hombres jóvenes de minorías sexuales (YSMM) de 17 a 24 años entre abril y septiembre de 2020 en los EE. UU. Uno de cada siete usuarios de PrEP YSMM interrumpió su uso durante la pandemia, y todos los que interrumpieron la PrEP informaron una disminución en la actividad sexual. El veinte por ciento informó tener dificultades para obtener recetas y medicamentos de sus médicos o farmacias, y más del 10% informó tener dificultades para acceder a las pruebas de VIH/ITS. Entre los que cumplieron con los criterios de los Centros para el Control y la Prevención de Enfermedades para la PrEP (n = 104), el 86,5% no estaba usando PrEP actualmente. Entre los encuestados 3 meses o más después del inicio de las principales medidas de COVID-19 para quedarse en casa (n = 165), el 35,8% informó CAS con una pareja causal en los últimos 3 meses durante la pandemia de COVID-19. La búsqueda de la prueba del VIH se asoció con la notificación de sexo anal sin condón en los 3 meses anteriores, lo que indica la necesidad de garantizar la continuidad de los servicios básicos de salud sexual para YSMM. No ajustar adecuadamente los servicios de prevención del VIH y la intervención frente a la adversidad relacionada con la pandemia socava los esfuerzos para poner fin a la epidemia del VIH en los EE. UU.

Electrochemical immunosensor based on Cu(II)-tetrahydroxy-1,4-benzoquinone amplifier for carcinoembryonic antigen determination.

In order to solve the problems of unstable signal and fast decrease of response signal of traditional electroactive substances, we synthesized a new type of electroactive substances, so that they can cooperatively amplify the response signal of the immune sensor and further improve its sensitivity. The conductive organic ligand tetrahydroxy 1,4-benzoquinone (THQ) and Cu2+ were chelated to form a stable polymeric two-dimensional metal-organic framework material Cu-THQ. Cu-THQ is a new type of electroactive substance. Compared with the traditional electroactive substance, Cu-THQ not only has stronger Redox activity, but also better stability and biocompatibility. We carried out various electrochemical characterizations on Cu-THQ and further proved that the introduction of Cu2+ not only greatly enhanced the stability of THQ electrical signal, but also increased its signal response. The experimental results showed that the prepared immunosensor exhibited good linearity for the detection of carcinoembryonic antigen in the range 1 fg/mL to 40 ng/mL, with detection limits and sensitivity of 0.477 fg/mL and 14.81 µA/(ng/mL)/cm2, respectively.

Preparation of a pH-responsive controlled-release electrochemical immunosensor based on polydopamine encapsulation for ultrasensitive detection of alpha-fetoprotein.

To accomplish ultra-sensitive detection of alpha-fetoprotein(AFP), a novel electrochemical immunosensor using polydopamine-coated Fe3O4 nanoparticles (PDA@Fe3O4 NPs) as a smart label and polyaniline (PANI) and Au NPs as substrate materials has been created. The sensor has the following advantages over typical immunoassay technology: (1) The pH reaction causes PDA@Fe3O4 NPs to release Prussian blue (PB) prosoma while also destroying the secondary antibody label and immunological platform and lowering electrode impedance; (2) PB has a highly efficient catalytic effect on H2O2, allowing for the obvious amplification of electrical impulses; (3) PANI was electrodeposited on the electrode surface to avoid PB loss and signal leakage, which effectively absorbed and fixed PB while considerably increasing electron transmission efficiency. The sensor's detection limit was 0.254 pg·mL-1 (S/N = 3), with a detection range of 1 pg·mL-1 to 100 ng·mL-1. The sensor has a high level of selectivity, repeatability, and stability, and it is predicted to be utilized to detect AFP in real-world samples.

The application of the inexpensive and synthetically simple electrocatalyst CuFe-MoC@NG in immunosensors.

In this study, we used inexpensive and synthetically simple electrocatalysts as replacements for conventional precious metal materials to reduce hydrogen peroxide (H2O2). We for the first time developed N-doped graphene-coated CuFe@MoC using one-step calcination of binary Prussian blue analogues (PBAs) with Mo6+ cationic grafting precursors. The synergistic interaction of CuFe PBA and MoC increased the catalytically active sites for H2O2 reduction. The catalyst was optimized in terms of the ratio of CuFe PBA to Mo6+, PVP content, and calcination temperature to improve its catalytic activity. When it was used to construct an electrochemical immunosensor for carcinoembryonic antigen (CEA) detection, polydopamine (CuFe-MoC@NG@PDA) was coated on its outer surface to increase the antibody loading and MoS2-Au NPs were used as substrates to improve Ab1 immobilization and accelerate electron transfer at the electrode interface, thereby improving the response signal of the immunosensor. Its concentration was linearly related to the response signal from 10 fg mL-1 to 80 ng mL-1, and the lowest limit of detection was 3 fg mL-1. In addition, the immunosensor has acceptable selectivity and high stability. All data indicate that nanocomposites have electrocatalytic applications.

In-vitro and in-vivo monitoring of gold(III) ions from intermediate metabolite of sodium aurothiomalate through water-soluble ruthenium (II) complex-based luminescent probe.

Real-time monitoring of drug metabolism in vivo is of great significance to drug development and toxicology research. The purpose of this study is to establish a rapid and visual in vivo detection method for the detection of an intermediate metabolite of the gold (I) drug. Gold (I) drugs such as sodium aurothiomalate (AuTM) have anti-inflammatory effects in the treatment of rheumatoid arthritis. Gold(III) ions (Au3+) are the intermediate metabolite of gold medicine, and they are also the leading factor of side effects in the treatment of patients. However, the rapid reduction of Au3+ to Au+ by thiol proteins in organisms limits the in-depth study of metabolism of gold drugs in vivo. Here we describe a luminescence Au3+ probe (RA) based on ruthenium (II) complex for detecting Au3+ in vitro and in vivo. RA with large Stokes shift, good water solubility and biocompatibility was successfully applied to detect Au3+ in living cells and vivo by luminescence imaging, and to trap the fluctuation of Au3+ level produced by gold (I) medicine. More importantly, the luminescent probe was used to the detection of the intermediate metabolites of gold (I) drugs for the first time. Overall, this work offers a new detection tool/method for a deeper study of gold (I) drugs metabolite.