Homogeneous Immunosensor Based on Luminescence Resonance Energy Transfer for Glycated Hemoglobin Detection Using Upconversion Nanoparticles

We report an immunosensor based on luminescence resonance energy transfer (LRET) to detect homogeneous glycated hemoglobin (HbA1c). This system uses near-infrared (NIR)-to-visible rare-earth upconversion nanoparticles (UCNPs), such as NaYF₄:Yb³⁺, Er³⁺, as the donor and HbA1c as the acceptor. The HbA1c used as target molecules showed absorption at 541 nm, which corresponded with the emission of the UCNPs. When HbA1c was added, LRET occurred between the donor and acceptor under laser irradiation of 980 nm because of the specific recognition between the anti-HbA1c monocolonal antibody-functionalized UCNPs and HbA1c. In the absence of HbA1c, there was strong upconversion luminescence intensity; however, in its presence, the distance between the donor and acceptor decreased to enable energy transfer, consequently quenching the luminescence of the UCNPs. The proposed method was successfully applied to HbA1c detection in blood samples. Our results indicate that the LRET-based immunosensor allows for specific and sensitive detection of HbA1c in a homogeneous manner

Absorption-Modulated SiO₂@Au Core–Satellite Nanoparticles for Highly Sensitive Detection of SARS-CoV‑2 Nucleocapsid Protein in Lateral Flow Immunosensors

The worldwide spread of coronavirus disease 2019 (COVID-19) highlights the need for rapid, simple, and accurate tests to detect various variants of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The antigen test, based on the lateral flow immunoassay (LFI), is a suitable “first line of defense” test that enables early identification and timely isolation of patients to minimize viral transmission among communities. However, it is generally less accurate than nucleic acid testing, and its sensitivity needs improvement. Here, a novel rapid detection method is designed to sensitively detect SARS-CoV-2 using isolated gold nanoparticle (AuNP)-assembled SiO2 core–satellite nanoparticles (SiO2@Au CSNPs). Well-grown AuNP satellites in the synthesis of SiO2@Au CSNPs significantly enhanced their light absorption, increased the detection sensitivity, and lowered the detection limit by 2 orders of magnitude relative to conventional gold colloids. The proposed system enabled highly sensitive detection of the SARS-CoV-2 nucleocapsid protein with a detection limit of 0.24 pg mL–1 within 20 min. This is the first study to develop a highly sensitive antigen test using the absorption-modulated SiO2@Au CSNPs. Our findings demonstrate the capacity of this platform to serve as an effective sensing strategy for managing pandemic conditions and preventing the spread of viral infections

Ultrasensitive Detection of Escherichia coli O157:H7 by Immunomagnetic Separation and Selective Filtration with Nitroblue Tetrazolium/5-Bromo-4-chloro-3-indolyl Phosphate Signal Amplification

Here, we report an enhanced colorimetric method using enzymatic amplification with nitroblue tetrazolium (NBT)/5-bromo-4-chloro-3-indolyl phosphate (BCIP) precipitation for the ultrasensitive detection of Escherichia coli O157:H7 through immunomagnetic separation-selective filtration. Biotinylated anti-E. coli O157:H7 antibody and streptavidin–alkaline phosphatase were conjugated to the surface of magnetic nanoparticles, and E. coli O157:H7-conjugates complexes remained on the membrane filter surface. The resultant light brown spots on the membrane filter were amplified with NBT/BCIP solution to yield enzyme-catalyzed precipitation, which increased with an increasing E. coli O157:H7 concentration. E. coli O157:H7 was detected in pure samples with limits of detection of 10 and 6.998 colony-forming units (CFU)/mL through visual observation and measurement of optical density, respectively. The proposed method was applied to a lettuce sample inoculated with selective E. coli O157:H7, which was detected within 55 min without cross-reactivity to non-target bacteria. This enhanced colorimetric method has potential for on-site detection of food contaminants and environmental pollutants

Plasmonic Approach to Fluorescence Enhancement of Mesoporous Silica-Coated Gold Nanorods for Highly Sensitive Influenza A Virus Detection Using Lateral Flow Immunosensor

Rapid diagnostic tests based on the lateral flow immunoassay (LFI) enable early identification of viral infection, owing to simple interpretation, short turnaround time, and timely isolation of patients to minimize viral transmission among communities. However, the LFI system requires improvement in the detection sensitivity to match the accuracy of nucleic acid amplification tests. Fluorescence-based LFIs are more sensitive and specific than absorption-based LFIs, but their performance is significantly affected by fundamental issues related to the quantum yield and photobleaching of fluorophores. Metal-enhanced fluorescence (MEF), which is a plasmonic effect in the vicinity of metallic nanoparticles, can be an effective strategy to improve the detection sensitivity of fluorescence-based LFIs. The key factors for obtaining a strong plasmonic effect include the distance and spectral overlap of the metal and fluorophore in the MEF system. In this study, MEF probes were designed based on core–shell nanostructures employing a gold nanorod core, mesoporous silica shell, and cyanine 5 fluorophore. To optimize the efficiency of MEF probes incorporated on the LFI platform (MEF-LFI), we experimentally and theoretically investigated the distance dependence of plasmonic coupling between cyanine 5 and gold nanorods by adjusting the shell thickness, resulting in significant fluorescence enhancement. The proposed MEF-LFI enabled highly sensitive detection of influenza A virus (IAV) nucleocapsid protein with a detection limit of 0.52 pg mL–1 within 20 min and showed high specificity and accuracy for determining IAV clinical samples. Overall, our findings demonstrate the potential of this method as an effective tool for molecular diagnosis under emergency conditions

sj-docx-1-tar-10.1177_17534666241232263 – Supplemental material for Ability of the modified NUTRIC score to predict mortality in patients requiring short-term versus prolonged acute mechanical ventilation: a retrospective cohort study

Supplemental material, sj-docx-1-tar-10.1177_17534666241232263 for Ability of the modified NUTRIC score to predict mortality in patients requiring short-term versus prolonged acute mechanical ventilation: a retrospective cohort study by Wanho Yoo, Hyojin Jang, Hayoung Seong, Saerom Kim, Soo Han Kim, Eun-Jung Jo, Jung Seop Eom and Kwangha Lee in Therapeutic Advances in Respiratory Disease</p

Baseline patient characteristics.

Baseline patient characteristics.</p

Factors affecting late initiation of appropriate treatment (≥ 60 days from the first institution visit).

Factors affecting late initiation of appropriate treatment (≥ 60 days from the first institution visit).</p

Additional file 1: of Clinical outcomes of radial probe endobronchial ultrasound using a guide sheath for diagnosis of peripheral lung lesions in patients with pulmonary emphysema

Table S1. The affecting factors for diagnostic yield of EBUS-GS in moderate-to-severe pulmonary emphysema. (DOCX 17 kb

Annual trends in the time from the first institution visit to initiation of appropriate treatment, and the proportion of patients who underwent line probe assays or Xpert MTB/RIF assays.

INH, isoniazid; LPA, line probe assay; PNUH, Pusan National University Hospital; RIF, rifampin. *Data are presented as the median.</p