Target-Modulated Hydrophobic Precipitation in Photocatalytic Nanochannels for Sensitive Detection of Alpha Fetoprotein

Association between urinary metals and prostate-specific antigen in aging population with depression: a cross-sectional study

Objective

This study aims to investigate the impact of depression and urinary metals on Prostate-Specific Antigen (PSA).

Methods

Analysis was conducted on 1901 samples collected from the National Health and Nutrition Examination Survey (NHANES) database between 2001 and 2010. Analytical methods included stepwise multiple linear regression (MLR) analysis of the overall population's urinary metals and PSA relationship, analysis of urinary metals and PSA relationship in older adults and BMI subgroups, analysis of urinary metals and PSA relationship in the depressed population, and restricted cubic spline (RCS) analysis. A significance level of p < 0.05 was considered statistically significant.

Results

In the stepwise multiple linear regression, beryllium (Be) showed a dose-response association with PSA (third quartile: β = 0.05, 95%CI (0.02, 0.09); fourth quartile: β = 0.07, 95%CI (0.02, 0.12), p trend = 0.048). Subgroup analysis indicated that in individuals aged >60, Be at Q4 level [β = 0.09, 95%CI (0.05, 0.21)] exhibited a dose-response correlation with PSA. In the population with 25 ≤ BMI < 30, Be might more significantly elevate PSA, with Q4 level having a pronounced impact on PSA levels [β = 0.03, 95%CI (0.02, 1.27)]. In the depressed population, urinary cadmium (Cd) levels showed a significant positive dose-response relationship, with Q4 level of Cd having the maximum impact on PSA [β = 0.3, 95%CI (0.09, 0.49)].

Conclusion

Individuals exposed to beryllium (Be), especially the older adults and overweight, should monitor their PSA levels. In depressed patients, cadmium (Cd) levels may further elevate PSA levels, necessitating increased monitoring of PSA levels among males.

Pore-Forming Toxin-Driven Recovery of Peroxidase-Mimicking Activity in Biomass Channels for Label-Free Electrochemical Bacteria Sensing

The development of sensitive, selective, and rapid methods to detect bacteria in complex media is essential to ensuring human health. Virulence factors, particularly pore-forming toxins (PFTs) secreted by pathogenic bacteria, play a crucial role in bacterial diseases and serve as indicators of disease severity. In this study, a nanochannel-based label-free electrochemical sensing platform was developed for the detection of specific pathogenic bacteria based on their secreted PFTs. In this design, wood substrate channels were functionalized with a Fe-based metal-organic framework (FeMOF) and then protected with a layer of phosphatidylcholine (PC)-based phospholipid membrane (PM) that serves as a peroxidase mimetic and a channel gatekeeper, respectively. Using Staphylococcus aureus (S. aureus) as the model bacteria, the PC-specific PFTs secreted by S. aureus perforate the PM layer. Now exposed to the FeMOF, uncharged 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonate) (ABTS) molecules in the electrolyte undergo oxidation to cationic products (ABTS•+). The measured transmembrane ionic current indicates the presence of S. aureus and methicillin-resistant S. aureus (MRSA) with a low detection limit of 3 cfu mL-1. Besides excellent specificity, this sensing approach exhibits satisfactory performance for the detection of target bacteria in the complex media of food.

Biosensing of Alpha-Fetoprotein: A Key Direction toward the Early Detection and Management of Hepatocellular Carcinoma

Hepatocellular carcinoma (HCC) is currently one of the most prevalent cancers worldwide. Associated risk factors include, but are not limited to, cirrhosis and underlying liver diseases, including chronic hepatitis B or C infections, excessive alcohol consumption, nonalcoholic fatty liver disease (NAFLD), and exposure to chemical carcinogens. It is crucial to detect this disease early on before it metastasizes to adjoining parts of the body, worsening the prognosis. Serum biomarkers have proven to be a more accurate diagnostic tool compared to imaging. Among various markers such as nucleic acids, circulating genetic material, proteins, enzymes, and other metabolites, alpha-fetoprotein (AFP) is a protein marker primarily used to diagnose HCC. However, current methods need a large sample and carry a high cost, among other challenges, which can be improved using biosensing technology. Early and accurate detection of AFP can prevent severe progression of the disease and ensure better management of HCC patients. This review sheds light on HCC development in the human body. Afterward, we outline various types of biosensors (optical, electrochemical, and mass-based), as well as the most relevant studies of biosensing modalities for non-invasive monitoring of AFP. The review also explains these sensing platforms, detection substrates, surface modification agents, and fluorescent probes used to develop such biosensors. Finally, the challenges and future trends in routine clinical analysis are discussed to motivate further developments.

NLISA versus enzyme-linked immunosorbent assay: Nanozyme-linked immunosorbent array based on platinum sub-nanocluster nanozyme for α-fetoprotein detection

Rapid and accurate identification of tumor metabolic markers is important for early tumor diagnosis and individualized treatment. Here, a stable monodisperse sub-nanometer platinum (Pt) material was developed as a highly efficient nanozyme with a specific activity of peroxidase as high as 20.86 U mg-1 through the growth of in situ domain-limited Pt quantum dots via the polymer polyvinylpyrrolidone. Further, the synthesis of large quantities of Pt-loaded SiO2 (Pt-SiO2 ) was determined by silylation reaction and used for naked eye colorimetric testing of human alpha-fetoprotein (AFP). In particular, the immunization incubation process occurred in preprepared microplates. A nanozyme-based immunomodel was constructed in the presence of the target AFP, and a chromogenic reaction occurred with exogenous hydrogen peroxide and the chromogenic substrate tetramethylbenzidine. On optimization of experimental conditions, the dynamic working response range for AFP was found to be 0.05-20 ng mL-1 , with a limit of detection of 38.7 pg mL-1 . This work provides a new strategy to design efficient nanozyme-based enzyme-linked immunochromatographic platforms to meet the practical use of replacing natural enzymes.

Target-triggered cascade signal amplification in nanochannels: An ingenious strategy for ultrasensitive photoelectrochemical DNA bioanalysis

Artificial solid-state nanochannels have aroused intense interests in biosensors and bioelectronics because of their special architectures. Herein, we pioneered an ingenious approach of target-triggered cascade signal amplification in porous anodic aluminum oxide (AAO) nanochannels for ultrasensitive photoelectrochemical (PEC) DNA bioanalysis. In the design, AAO nanochannels were modified initially with capture DNA (cDNA) and then incorporated with a photoelectrode, yielding the desired architecture of highly ordered nanoarrays on top of the signal transducer. For target DNA (tDNA) probing, exonuclease III (Exo-III) mediated target recycling (ETR) was first activated to generate plenty of output DNA (oDNA) fragments. After oDNA and the conjugate of Au-labeled probe DNA (Au-pDNA) were anchored within the nanochannels via DNA hybridization, in-situ synthesis of Ag shells on tethered Au nanoparticles was conducted. The resulting large-sized Au@Ag core-shell nanostructure within the nanochannels would cause conspicuous blocking effect to hinder the transportation of electrons accessing the photoelectrode. Since the signal inhibition was directly related to tDNA concentration, an innovative nanochannels PEC DNA assay was exploited and qualified for ultrasensitive detection. The anti-interference ability of this platform was also emphasized by the split AAO membrane for biological incubation without participation of the photoelectrode. This featured nanochannels PEC strategy with cascade amplification launched a novel detecting platform for trace levels of DNA, and it could spark more inspiration for a follow-up exploration of other smart nanochannels PEC bioassays.

Tunable nanochannel resistive pulse sensing device using a novel multi-module self-assembly

Nanochannel-based resistive pulse sensing (nano-RPS) system is widely used for the high-sensitive measurement and characterization of nanoscale biological particles and biomolecules due to its high surface to volume ratio. However, the geometric dimensions and surface properties of nanochannel are usually fixed, which limit the detections within particular ranges or types of nanoparticles. In order to improve the flexibility of nano-RPS system, it is of great significance to develop nanochannels with tunable dimensions and surface properties. In this work, we proposed a novel multi-module self-assembly (MS) strategy which allows to shrink the geometric dimensions and tune surface properties of the nanochannels simultaneously. The MS-tuned nano-RPS device exhibits an enhanced signal-to-noise ratio (SNR) for nanoparticle detections after shrunk the geometric dimensions by MS strategy. Meanwhile, by tuning the surface charge, an enhanced resolution for viral particles detection was achieved with the MS-tuned nano-RPS devices by analyzing the variation of pulse width due the tuned surface charge. The proposed MS strategy is versatile for various types of surface materials and can be potentially applied for nanoscale surface reconfiguration in various nanofluidic devices.

Photoredox-Promoted Co-Production of Dihydroisoquinoline and H2 O2 over Defective Zn3 In2 S6

One of the most sustainable and promising approaches for hydrogen peroxide (H₂ O₂ ) production in a low-cost and environment-friendly way is photosynthesis, which, however, suffers from poor carrier utilization and low H₂ O₂ productivity. The addition of proton donors such as isopropanol or ethanol can increase H₂ O₂ production, which, unfortunately, will inevitably elevate the entire cost while wasting the oxidizing power of holes (h⁺ ). Herein, the tetrahydroisoquinolines (THIQs) is employed as a distinctive proton donor for the thermodynamically feasible and selective semi-dehydrogenation reaction to highly valuable dihydroisoquinolines (DHIQs), and meanwhile, to couple with and promote H₂ O₂ generation in one photoredox reaction under the photocatalysis by dual-functional Zn₃ In₂ S₆ photocatalyst. Surprisingly, the suitably defective Zn₃ In₂ S₆ offers an excellent and near-stoichiometric co-production performance of H₂ O₂ and DHIQs at unprecedentedly high rates of 66.4 and 62.1 mmol h^-1 g^-1 under visible light (λ ≥ 400 nm), respectively, which outperforms all the previously available reports even though sacrificial agents were employed in those reports. Additionally, photocatalytic redox reaction mechanism demonstrates that H₂ O₂ can be generated through multiple pathways, highlighting the synergistic effect among ROS (·O₂ ^- and ¹ O₂ ), h⁺ and proton donor, which has been ignored in previous studies.