查看更多>>摘要：Aspergillus species continue to be an important cause of life-threatening infection in immunocompromised patients and galactomannan (GM) is a popular biomarker in the diagnosis of invasive aspergillosis (IA). Here we developed and validated an amplified luminescent proximity homogenous assay-linked immunosorbent assay (AlphaLISA) for serum and bronchoalveolar fluid (BALF) GM based on this approach. Technological processes and reaction conditions were optimized. Study assessments included reproducibility, accuracy, stability, and cross reactivity experiments. Method comparisons with the commercial Platelia Aspergillus enzyme immunoassay (Bio-Rad Laboratories) were performed using 201 clinical serum and BALF samples. Under the optimized conditions, the total runtime of the AlphaLISA method was 40 min with simple operation. The percent coefficient variations (CVs%) were lower than 15%, and the recoveries were in the range of 90-110%. Of note, the proposed assay exhibited acceptable stability and did not display cross-reactivity with non Aspergillus pathogens. Compared with the results from the Platelia kit, there was a satisfied overall qualitative agreement of 97.5% and overall quantitative correlation coefficient of 0.59. In all, we have successfully developed an alternative novel homogeneous nanoparticle-based immunoassay, which has shorter incubation time and easier protocol than the ones of conventional ELISA. It could serve as an alternative to the well-established Platelia assay for measurement of GM in serum and BALF.
查看更多>>摘要：In this work, novel dual-targeting probes composed of galactose and morpholine were designed and synthesized for monitoring Fe3+ levels in the lysosome of hepatocyte. MP-Gal -1, MP-Gal -2 and MP-Gal -3 showed good selectivity and sensitivities toward Fe3+ with the detection limits of 9.40 x 10(-8) M, 7.68 x 10(-8) M and 7.10 x 10(-8) M, respectively. 1:2 stoichiometry is the most likely recognition mode between probe and Fe3+. Low toxic MP-Gal -1, MP-Gal -2 and MP-Gal -3 exhibited favorable hepatic targeting effect in both cell and tissue levels, which was because the galactose group of probe could be recognized by ASGPR overexpressed on the hepato-cytes. The hepatocyte-targeting capacity followed MP-Gal-1 < MP-Gal-2 < MP-Gal-3 trend, which was attributed to the galactose cluster effect. MP-Gal -1, MP-Gal-2 and MP-Gal -3 also displayed good lysosomes-targeting capacities, because the basic morpholine moiety of probes could be easily attracted by the acidic lysosome. Therefore, MP-Gal -1, MP-Gal -2 and MP-Gal-3 have good dual targeting capacities (liver and lyso-some) and could be used to detect lysosomal Fe3+ in the liver, which is great significant for precise diagnosis and treatment of liver lysosomal iron-related diseases.
查看更多>>摘要：We present a fast, reliable and easy to scale-up colorimetric sensor based on gold nanoparticles (AuNPs) to detect the sequences coding for the RdRp, E, and S proteins of SARS-CoV-2. The optimization of the system (so-called "the sensor") includes the evaluation of different sizes of nanoparticles, sequences of oligonucleotides and buffers. It is stable for months without any noticeable decrease in its activity, allowing the detection of SARS-CoV-2 sequences by the naked eye in 15 min. The efficiency and selectivity of detection, in terms of significative colorimetric changes in the solution upon target recognition, are qualitatively (visually) and quantitatively (absorbance measurements) assessed using synthetic samples and samples derived from infected cells and patients. Furthermore, an easy and affordable amplification approach is implemented to increase the system's sensitivity for detecting high and medium viral loads (>= 10(3) - 10(4) viral RNA copies/mu l) in patient samples. The whole process (amplification and detection) takes 2.5 h. Due to the ease of use, stability and minimum equipment requirements, the proposed approach can be a valuable tool for the detection of SARS-CoV-2 at facilities with limited resources.
查看更多>>摘要：A rhodamine-based fluorescent probe (Rho-GSH) was rationally designed and synthesized, using nitrobenzene as recognition group for monitoring and imaging GSH in vitro and in vivo. In the presence of GSH, Rho-GSH undergoes sequential nucleophilic substitution and spiro-ring-opening reaction, resulting the fluorescence increase of probe, which enables quantitative detection of GSH with "off-on " fluorescence. The cascade reaction also enables Rho-GSH to rapidly detect GSH (3 s). In addition, Rho-GSH exhibited outstanding selectivity in detecting GSH vs cysteine (Cys) and homocysteine (Hcy). Based on the outstanding detection performance and superior biocompatibility of Rho-GSH, it was used to visualize GSH in vitro and in vivo, demonstrating its highly selectivity for GSH detection (with respect to Cys and Hcy). Rho-GSH can help visually distinguishing cancer cells from normal cells by fluorescence imaging, demonstrating the overexpression of GSH in cancer cells. Because of the outstanding analytical capabilities of Rho-GSH for GSH detection, Rho-GSH may be useful for cancer diagnosis and clinical evaluation.
查看更多>>摘要：A nanostructured surface composed of SiO2 nanoparticles (200 nm) deposited on fiberglass was used as a platform for immobilization of NAD(+)-dependent enzymes (alcohol and glucose dehydrogenases). The surface functionalized with the enzymes was further loaded with NAD(P)(+)cofactor and 1-methoxy-5-methylphenazinium methyl sulfate (MPMS) redox species. The designed biocatalytic system was used for fluorescent analysis of substrates (ethanol and glucose used as example analyte substances). Importantly, the output analytical signal was obtained by processing fluorescent images of the sensing spots using a smartphone for handling and digitizing the images. The designed sensing interface is suggested as a universal analytical platform which can be used with many different NAD(+)-dependent enzymes. The present biosensing/bioanalytic system was studied as a proof-of-the-concept, rather than as a practically important ethanol or glucose biosensor. Many more practically important biosensors based on the same universal platform can be designed with different enzymes for various biomedical, forensic, and homeland security applications as well as environmental monitoring.
NSTL
Elsevier