Development of High-Performance and Multifunctional Nanoparticles Powered the Integrated Diagnosis and Treatment of Escherichia coli O157:H7.

Pathogenic diseases that trigger food safety remain a noteworthy concern due to substantial public health, economic, and social burdens worldwide. It is vital for developing an integrated diagnosis and treatment strategy for bacteria, which could achieve quick detection of pathogenic bacteria and the inhibition of multidrug-resistant bacteria. Herein, we reported an organic molecule (M-3) possessed strong light capture capacity, emerging a low energy gap and ΔEST. Subsequently, M-3 was integrated into a nanostructured system (BTBNPs) with excellent ROS generation, light absorption capability, and photothermal performance. Reactive oxygen species (ROS) generated by BTBNPs were mainly free radicals from a type I mechanism, and the high photothermal conversion efficiency of BTBNPs was 41.26%. Benefiting from these advantages of BTBNPs, BTBNPs could achieve a ∼99% antibacterial effect for Escherichia coli O157:H7 with 20 µM dosage and 5 min of irradiation. Furthermore, the limit of detection (LoD) of the proposed BTBNPs-LFIA (colorimetric and photothermal modalities) for detecting E. coli O157:H7 was 4105 and 419 CFU mL-1, respectively. Overall, this work is expected to provide a new and sophisticated perspective for integrated diagnosis and treatment systems regarding pathogenic bacteria.

Efficient Photothermal Sensor Based on Coral-Like Hollow Gold Nanospheres for the Sensitive Detection of Sulfonamides.

Gold nanoparticles (AuNPs), universally regarded as colorimetric signal reporters, are widely employed in lateral flow immunoassays (LFIAs). However, it is difficult for AuNPs-LFIA to achieve a wide range and sensitive detection. Herein, novel coral-like hollow gold nanospheres (CHGNPs) are synthesized. The growth of gold nanospheres can be regulated to obtain a multibranched and hollow construction. The obtained CHGNPs possess intense broadband absorption across the visible to near-infrared region, exhibiting a high molar extinction coefficient of 14.65 × 1011 M-1 cm-1 and a photothermal conversion efficiency of 79.75%. Thus, the photothermal/colorimetric dual-readout LFIA is developed based on CHGNPs (CHGNPs-PT-LFIA and CHGNPs-CM-LFIA) to effectively improve the detection sensitivity and broaden the detection range in regard to sulfonamides (SAs). The limits of detection of the CHGNPs-PT-LFIA and CHGNPs-CM-LFIA reached 1.9 and 2.8 pg mL-1 for the quantitative detection of sulfaquinoxaline, respectively, which are 6.3-fold and 4.3-fold lower than that of the AuNPs-LFIA. Meanwhile, the CHGNPs-PT-LFIA broadened the detection range to three orders of magnitude, which ranged from 2.5 to 5000 pg mL-1 . The synthesized photothermal CHGNPs have been proven effective in improving the performance of the LFIA and provide a potential option for the construction of sensing platforms.

"Four-In-One" Multifunctional Dandelion-Like Gold@platinum Nanoparticles-Driven Multimodal Lateral Flow Immunoassay.

The traditional lateral flow immunoassay (LFIA) with a single signal output mode may encounter challenges such as low sensitivity, poor detection range, and susceptibility to external interferences. These limitations hinder its ability to meet the growing demand for advanced LFIA. To address these issues, the rational development of multifunctional labels for multimodal LFIA emerges as a promising strategy. Herein, this study reports a multimodal LFIA using "four-in-one" multifunctional dandelion-like gold@platinum nanoparticles (MDGP). The inherent properties of MDGP, such as the broad absorption spectrum, porous dandelion-like nanostructure, and bimetallic composition with gold and platinum, endow them with capacities in dual spectral-overlapped fluorescence quenching, optical readout, catalytic activity, and photothermal effect. Benefiting from their multifunctional properties, the MDGP-LFIA enables multimodal outputs including fluorescent, colorimetric, and photothermal signals. This multimodal MDGP-LFIA allows for the detection of acetamiprid at a range of 0.01-50 ng mL-1 , with the lowest qualitative and quantitative detection results of 0.5 and 0.008 ng mL-1 , respectively, significantly better than the traditional gold nanoparticles-based LFIA. The diversity, complementarity, and synergistic effect of integrated output signals in this multimodal MDGP-LFIA improve the flexibility, practicability, and accuracy of detection, holding great promise as a point-of-care testing platform in versatile application scenarios.

Sensitive fluorescence ELISA for the detection of zearalenone based on self-assembly DNA nanocomposites and copper nanoclusters.

Zearalenone (ZEN), produced by Fusarium species, is a potential risk to human health. Traditional enzyme-linked immunosorbent assay (ELISA) is restricted due to low sensitivity for the detection of ZEN. Herein, enzyme nanocomposites (ALP-SA-Bio-ssDNA, ASBD) were prepared with the self-assembly strategy based on streptavidin-labeled alkaline phosphatase (SA-ALP) and dual-biotinylated ssDNA (B2-ssDNA). The enzyme nanocomposites improved the loading amount of ALP and catalyzed more ascorbic acid 2-phosphate to generate ascorbic acid (AA). Subsequently, Cu2+ could be reduced to copper nanoclusters (CuNCs) having strong fluorescence signal by AA with poly T. Benefiting from the high enzyme load of nanocomposites and the strong signal of CuNCs, the fluorescence ELISA was successfully established for the detection of ZEN. The proposed method exhibited lower limit of detection (0.26 ng mL-1) than traditional ELISA (1.55 ng mL-1). The recovery rates ranged from 92.00% to 108.38% (coefficient of variation < 9.50%) for the detection of zearalenone in corn and wheat samples. In addition, the proposed method exhibited no cross reaction with four other mycotoxins. This proposed method could be used in trace detection for food safety.

Phage based magnetic capture method as an aid for real time RPA detection of Salmonella spp. in milk.

Salmonella is a major cause of foodborne diseases worldwide. Conventional rapid assays for detecting Salmonella in real samples often encounter severe matrix interference or detect the limited number of species of a genus, resulting the inaccuracy of detection. In this study, we developed a method that combined phage-based magnetic capture with real time recombinase polymerase amplification (RPA) for the rapid, highly sensitive, and specific detection of Salmonella in milk with an ultra-low detection limit. The Felix O-1 phage-conjugated magnetic beads (O-1 pMBs) synthesized in this method showed excellent capture ability for Salmonella spp. and ideal specificity for non-Salmonella strains. After O-1 pMBs-based magnetic separation, the limit of detection (LOD) of the real time RPA assay was 50 cfu/mL in milk samples, which was significantly increased by a magnitude of 3-4 orders. The method exhibited a high sensitivity (compatibility) of 100% (14/14) for all tested Salmonella serotype strains and an ideal specificity (exclusivity) of 100% (7/7) for the tested non-Salmonella strains. The entire detection process including Salmonella capture, DNA extraction, and real time RPA detection was completed within 1.5 h. Furthermore, milk samples spiked with 10 cfu/25 mL of Salmonella were detected positive after cultured in buffered peptone water for only 3 h. Therefore, the proposed method could be an alternative for the rapid and accurate detection of Salmonella.

High-Performance Fluorescent Microspheres Based on Fluorescence Resonance Energy Transfer Mode for Lateral Flow Immunoassays.

The label with a large Stokes shift and strong fluorescence properties could improve the sensitivity of the lateral flow immunoassay (LFIA). Herein, two aggregation-induced emission (AIE) luminogens with spectral overlap were encapsulated in polymers by using the microemulsion method as a label, and the construction of a fluorescence resonance energy transfer mode was further verified via theoretical calculation and spectral analysis. Satisfactorily, the doped AIE polymer microspheres (DAIEPMs) exhibited a large Stokes shift of 285 nm and a 10.8-fold fluorescence enhancement compared to those of the AIEPMs loaded with acceptors. Benefiting from the excellent optical performance, DAIEPMs were applied to the LFIA for sensitive detection of chlorothalonil, which is an organochlorine pesticide. The limit of detection of the proposed DAIEPMs-LFIA was 1.2 pg/mL, which was 4.8-fold and 11.6-fold lower than those of quantum dot bead LFIA and gold nanoparticle LFIA, respectively. This work provides a new strategy to improve the optical properties of fluorescent materials and construct a sensitive and reliable detection platform.

Polyethyleneimine-induced fluorescence enhancement strategy for AIEgen: the mechanism and application.

Aggregation-induced emission luminogens (AIEgens) are attracting extensive research attention in the biosensor fields. Herein, we report a new polyethyleneimine (PEI)-induced strategy for enhancing luminescence of TCBPE (an AIEgen) to promote its development in biosensor. The copolymer dots (TCBPE-PEI) with high quantum yield (39.7%) and outstanding stability were synthesized via a one-pot method. The fluorescence enhancement mechanism based on the PEI strategy originated from the restriction of intramolecular motions of TCBPEs and the form of donor-acceptor structures to decrease the inherent energy bandgap. Benefiting from chelating property of TCBPE-PEI by Cu2+, a fluorescence-quenching sensor for Cu2+ detection was developed based on the fluorescence quenching of the electron transfer effect. Especially, a good linear range of 10-250 nM with a low limit of detection 1.1 nM was achieved, and it was further applied in samples successfully. The current work provides a novel approach to fabricate AIEgen biosensors and shows great potential in Cu2+ detection.

A multiple lateral flow immunoassay based on AuNP for the detection of 5 chemical contaminants in milk.

Melamine (MEL), enrofloxacin (ENR), sulfamethazine (SMZ), tetracycline (TC), and aflatoxin M1 (AFM1) are the main chemical contaminants in milk. It is necessary to detect these miscellaneous chemical contaminants in milk synchronously to ensure the safety of the milk. In this study, a multiple lateral flow immunoassay (LFIA) was developed for the detection of MEL, ENR, SMZ, TC, and AFM1 in milk. Under optimal experimental conditions, the cutoff values were 25 ng/mL for MEL, 1 ng/mL for ENR, 2.5 ng/mL for SMZ, 2.5 ng/mL for TC, and 0.25 ng/mL for AFM1 in milk samples. The limits of detection of LFIA were 0.173 ng/mL for MEL, 0.078 ng/mL for ENR, 0.059 ng/mL for SMZ, 0.082 ng/mL for TC, and 0.0064 ng/mL for AFM1. The recovery rates of LFIA in milk were 83.2-104.4% for MEL, 76.5-127.3% for ENR, 96.8-113.5% for SMZ, 107.1-166.6% for TC, and 93.5-130.3% for AFM1. The coefficients of variation were all less than 15%. As a whole, the developed multiple lateral flow immunoassay showed potential as a highly reliable and excellent tool for the rapid and sensitive screening of MEL, ENR, SMZ, TC, and AFM1 in milk.

Sensitive fluorescence ELISA with streptavidin scaffolded DNA tetrads for the detection of Escherichia coli O157:H7.

Escherichia coli O157:H7 poses a threat to humans. Traditional ELISA is not a sensitive method for the detection of E. coli O157:H7. Here, an efficient method was designed for improving the load capacity of alkaline phosphatase (ALP) with streptavidin scaffolded DNA tetrad (SS-DNAt). With more ALP, more ascorbic acid 2-phosphate was catalyzed to ascorbic acid that was used to synthesize fluorescence poly adenine-thymine-templated copper nanoclusters. Based on SS-DNAt, fluorescence ELISA was successfully proposed for improving the sensitivity for detection of E. coli O157:H7 in milk samples. The method showed a linear range of 104 to 106 cfu/mL. The limit of detection of fluorescence ELISA was 3.75 × 103 cfu/mL and 6.16-fold better than that of traditional ELISA. The recovery of the fluorescence ELISA was 86.7 to 93.6% with the coefficient of variation of 5.6 to 10.5% in milk. This method could be used to detect hazardous material in food.

Lateral flow immunoassay based on polydopamine-coated metal-organic framework for the visual detection of enrofloxacin in milk.

Herein, we report a new polydopamine (PDA)-coated metal-organic framework (MOF) as a label to improve the sensitivity of lateral flow immunoassay (LFIA). The MOF, UiO-66-NH2, was synthesized via the hydrothermal method, and it exhibited the advantageous features of ordered pore structure, strong absorbance, and high specific surface area. Subsequently, UiO-66-NH2 was coated with PDA to improve the antibody coupling effectivity and light absorption ability. The optical intensity and antibody coupling efficiency of UiO-66@PDA were superior to those of gold nanoparticles (AuNPs). Under the optimum condition, the limit of detection and cutoff value of UiO-66@PDA-LFIA in detecting enrofloxacin were 0.045 and 1.0 ng/mL, respectively, which were lower than those of AuNPs-LFIA (0.095 and 5 ng/mL). The recoveries of UiO-66@PDA-LFIA in low-fat milk and whole milk were 85.6-107.4% and 79.3-115.5%, respectively, with coefficients of variation of 2.91-9.59% and 3.91-11.8%, respectively, as further confirmed by liquid chromatography-tandem mass spectrometry. These results indicate that UiO-66@PDA can be used as a novel probe for LFIA development and applications. Graphical abstract.

I2/I--mediated fluorescence quenching of an Ag+-doped gold nanocluster-based immunoassay for sensitive detection of Escherichia coli O157:H7 in milk.

Escherichia coli O157:H7 is a type of hazardous bacteria in the field of food safety. A sensitive and effective method is urgently needed to detect it, avoiding enormous harm for the human health. In this study, we synthesized stable Ag+-doped gold nanoclusters (Ag-AuNC) with a fluorescence intensity 4.8 times stronger than that of AuNC. It was further demonstrated that Ag0 existing in the AuNC core and a fraction of Ag+ anchored on the AuNC shell eliminated the surface defects and improved the luminescent properties of AuNC. A combination of I2 and I- was used to quench fluorescence-enhanced Ag-AuNC, which was first applied in ELISA for detecting E. coli O157:H7 to improve the sensitivity. In the presence of E. coli O157:H7, the biotinylated anti-E. coli O157:H7 mAb and streptavidin-alkaline phosphatase would be immobilized and catalyze l-ascorbic acid 2-phosphate sesquimagnesium salt hydrate to produce ascorbic acid. After addition of KIO3, I2/I- were generated. The I2 could trigger oxidative etching of Ag-AuNC and I- could combine with Ag+ to decrease the Ag+ concentration of Ag-AuNC, which resulted in fluorescence quenching of Ag-AuNC. Under optimal conditions, the linear range of I2/I--mediated fluorescence quenching of Ag-AuNC-based immunoassay for detecting E. coli O157:H7 was 3.3 × 103 to 106 cfu/mL, with a detection limit of 9.2 × 102 cfu/mL, 10.7-fold lower than that of the traditional ELISA. The proposed immunoassay exhibits excellent sensitivity, specificity, recovery, and accuracy, which is useful for quantitative detection of E. coli O157:H7 in food safety.

Development of a rapid and sensitive quantum dot nanobead-based double-antigen sandwich lateral flow immunoassay and its clinical performance for the detection of SARS-CoV-2 total antibodies.

Owing to the over-increasing demands in resisting and managing the coronavirus disease 2019 (COVID-19) pandemic, development of rapid, highly sensitive, accurate, and versatile tools for monitoring total antibody concentrations at the population level has been evolved as an urgent challenge on measuring the fatality rate, tracking the changes in incidence and prevalence, comprehending medical sequelae after recovery, as well as characterizing seroprevalence and vaccine coverage. To this end, herein we prepared highly luminescent quantum dot nanobeads (QBs) by embedding numerous quantum dots into polymer matrix, and then applied it as a signal-amplification label in lateral flow immunoassay (LFIA). After covalently linkage with the expressed recombinant SARS-CoV-2 spike protein (RSSP), the synthesized QBs were used to determine the total antibody levels in sera by virtue of a double-antigen sandwich immunoassay. Under the developed condition, the QB-LFIA can allow the rapid detection of SARS-CoV-2 total antibodies within 15 min with about one order of magnitude improvement in analytical sensitivity compared to conventional gold nanoparticle-based LFIA. In addition, the developed QB-LFIA performed well in clinical study in dynamic monitoring of serum antibody levels in the whole course of SARS-CoV-2 infection. In conclusion, we successfully developed a promising fluorescent immunological sensing tool for characterizing the host immune response to SARS-CoV-2 infection and confirming the acquired immunity to COVID-19 by evaluating the SRAS-CoV-2 total antibody level in the crowd.

Immunochromatographic assay based on time-resolved fluorescent nanobeads for the rapid detection of sulfamethazine in egg, honey, and pork.

BACKGROUND: Sulfamethazine (SMZ), a veterinary drug widely used in animal husbandry, is harmful to human health when excess residues are present in food. In this study, a fast, reliable, and sensitive immunochromatographic assay (ICA) was developed on the basis of the competitive format by using time-resolved fluorescent nanobeads (TRFN) as label for the detection of SMZ in egg, honey, and pork samples. RESULTS: Under optimized working conditions, this method had limits of detection of 0.016, 0.049, and 0.029 ng mL-1 and corresponding linear ranges of 0.05 to 1.00, 0.05 to 5.00, and 0.05 to 1.00 ng mL-1 in egg, honey, and pork samples, respectively. The recovery experiments showed that the average recoveries ranged from 90.5% to 113.9%, 82.4% to 112.0%, and 79.8% to 93.4% with corresponding coefficients of variation of 4.1% to 11.7%, 7.5% to 11.5%, and 4.8% to 8.7% for egg, honey, and pork samples, respectively. The developed TRFN-ICA was also systematically compared with high-performance liquid chromatography coupled with tandem mass spectrometry (HPLC-MS/MS) by analyzing 45 actual samples from egg, honey, and pork. CONCLUSION: Overall, the developed TRFN-ICA had high reliability and excellent potential for the ultrasensitive detection of SMZ for food safety monitoring, also providing a universal platform for the on-site detection of other targets. © 2020 Society of Chemical Industry.

Green Enzyme-Linked Immunosorbent Assay Based on the Single-Stranded Binding Protein-Assisted Aptamer for the Detection of Mycotoxin.

In this work, a green enzyme-linked immunosorbent assay (ELISA) based on the single-stranded binding protein (SSB)-assisted aptamer was designed for biosensing applications. Combined with the biotin-streptavidin (SA) system and the high catalytic activity of horseradish peroxidase (HRP), this SSB-assisted aptamer sensor was applied for the detection of aflatoxin B1, ochratoxin A, and zearalenone. In this novel ELISA, mycotoxin-protein conjugations were replaced by SSB to avoid the hazard of mycotoxin, whereas antibodies were replaced by aptamer to avoid the complex and tedious preparation of antibodies. In the absence of target mycotoxins, SSB can bind the aptamer-biotin specifically. Detection was performed using the strong combination of biotin and SA after adding SA-HRP and substrate/chromogen solution, thereby resulting in a strong yellow color signal. In the presence of target mycotoxins, the aptamer-biotin cannot bind to the SSB, thereby leading to a weak yellow color signal. Under optimal conditions, the designed method was successfully applied for the determination of real sample and exhibited high specificity and low limits of detection in corn (112 ng L-1 for aflatoxin B1, 319 ng L-1 for ochratoxin A, and 377 ng L-1 for zearalenone). The green ELISA may also be extended to the detection of other biohazardous targets by changing the aptamer.

Sensitive immunoassays based on a monoclonal antibody for detection of marbofloxacin in milk.

Marbofloxacin (MBF) is a key class of synthetic fluoroquinolone antibiotic that is commonly used as a veterinary drug. However, excess residue of MBF in animal-derived food samples, such as milk, is harmful to consumers. In this study, 4 mAb against MBF, namely, M4E3, M7A6, M3C7, and M5C6, were produced. Indirect competitive (ic) ELISA revealed that the M4E3 exhibited the highest sensitivity with a half-maximal inhibitory concentration (IC50) of 0.07 ng/mL and a limit of detection of 0.01 ng/mL for detection of MBF. The results of the cross-reactivity experiment revealed that the M4E3 could detect lomefloxacin, ofloxacin, fleroxacin, pefloxacin, danofloxacin, and enrofloxacin sensitively with IC50 of 0.02, 0.07, 0.18, 0.27, 0.30, and 0.32 ng/mL, respectively. Meanwhile, a cross-reactivity experiment showed that the M4E3 had a crossover rate of more than 20% with these fluoroquinolone analogs. A weak crossover rate below 1.11% was observed with 14 other fluoroquinolone analogs. The recovery rate of MBF in milk ranged from 72.28% to 129.19%, which showed that the developed indirect competitive ELISA was effective in detecting MBF in milk. Furthermore, a visual colloidal gold-based immunochromatographic assay was developed for detecting MBF with a cut-off value of 1 ng/mL in both phosphate-buffered saline and a milk sample by using this mAb. Given this sensitive mAb, both indirect competitive ELISA and colloidal gold-based immunochromatographic assay could be effective screening tools for detection of MBF in milk.

Dual-mode immunoassay system based on glucose oxidase-triggered Fenton reaction for qualitative and quantitative detection of danofloxacin in milk.

In this study, a novel colorimetric and fluorescent dual-mode ELISA based on glucose oxidase (GOx)-triggered Fenton reaction was developed for the qualitative and quantitative detection of danofloxacin (DAN). In this system, streptavidin-linked biotinylated anti-DAN-monoclonal antibody (SA-Bio-mAb) and biotinylated GOx (Bio-GOx) form the immune complex mAb-Bio-SA-Bio-GOx. In the absence of DAN, the mAb-Bio-SA-Bio-GOx would be immobilized by combining with coated DAN-BSA and catalyzed glucose to generate H2O2. The Fenton reaction between H2O2 and Fe2+ generated hydroxyl radicals, which oxidized the o-phenylenediamine to 2,3-diamino-phenazine. A dual-signal immunoassay with colorimetry and fluorescence as the signal readout was established. In the presence of DAN, DAN and DAN-BSA competed with Bio-mAb, decreasing the connection between immune complexes and DAN-BSA and finally resulting in lower signal of colorimetry and fluorescence. Under optimal conditions, the limit of detection of the fluorescence immunoassay was 0.337 ng/mL and was 5.24-fold lower than that of traditional ELISA. The colorimetric immunoassay cut-off value was 30 ng/mL in milk. The average recoveries of the method for milk samples that are spiked with different concentrations of DAN were 91.1 to 128.3%, with a coefficient of variation of 0.7 to 8.2%. These results of the method exhibited good agreement with those of liquid chromatography-tandem mass spectrometry system (LC-MS/MS) method. In brief, this work provides an improved screening strategy with high sensitivity and accuracy for the qualitative or quantitative detection of DAN in milk monitoring.

Integrated gold superparticles into lateral flow immunoassays for the rapid and sensitive detection of Escherichia coli O157:H7 in milk.

Escherichia coli O157:H7 is a common harmful foodborne pathogen that can cause severe diseases at low infectious doses. Traditional lateral flow immunoassay (LFIA) for the rapid screening of E. coli O157:H7 in food suffers from low sensitivity due to its dependence on 20- to 40-nm gold nanoparticles (AuNP) with insufficient brightness as labels. To address this issue, we reported for the first time the successful synthesis of gold superparticles (GSP) by encapsulating numerous small AuNP into a polymer nanobead using an evaporation-induced self-assembly method. Results indicated that the resultant GSP exhibited remarkably enhanced absorbance compared with the most widely used 40 nm AuNP in LFIA. In addition, the absorbance of GSP could be easily tuned by varying GSP sizes. Under optimized conditions, we achieved a rapid and sensitive determination of E. coli O157:H7 in milk with a detection limit of 5.95 × 102 cfu/mL when using the GSP with a size of 342 nm as LFIA signal reporters, exhibiting improvement of approximately 32-fold relative to the conventional 40 nm AuNP-LFIA method. We further demonstrated the selectivity, accuracy, reliability, and practicality of the proposed GSP-LFIA strip. In summary, this work offers a new strategy for improving LFIA sensitivity using assembled GSP as markers and demonstrates huge potential in rapidly and sensitively detecting foodborne pathogens.

A genome-wide association study on lipoprotein (a) levels and coronary artery disease severity in a Chinese population.

Lipoprotein (a) [Lp(a)] is a genetically determined risk factor of coronary artery disease (CAD). Previous genome-wide association studies (GWASs), which were mostly carried out in Caucasians, have identified many Lp(a)-associated SNPs. Here, we performed a GWAS on Lp(a) levels and further explored the relationships between Lp(a)-associated SNPs and CAD severity in 1,403 Han Chinese subjects. We observed that elevated Lp(a) levels were significantly associated with the increased synergy between percutaneous coronary intervention with TAXUS and cardiac surgery (SYNTAX) score and the counts of heavily calcified lesions and long-range lesions (LRLs; P < 0.05), which are defined as lesions spanning >20 mm. Moreover, we identified four independent SNPs, namely, rs7770628, rs73596816, and rs6926458 in LPA, and rs144217738 in SLC22A2, that were significantly associated with Lp(a) levels. We also found that rs7770628 was associated with high SYNTAX scores [odds ratio (OR) (95% CI): 1.37 (1.05-1.80), P = 0.0213, false discovery rate (FDR) = 0.0852], and that rs7770628 and rs73596816 were associated with high risk of harboring LRLs [OR (95% CI): 1.53 (1.17-2.01), P = 0.0018, FDR = 0.0072 and 1.72 (1.19-2.49), P = 0.0040, FDR = 0.0080, respectively]. Our study was a large-scale GWAS to identify Lp(a)-associated variants in the Han Chinese population. Our findings highlight the importance and potential of Lp(a) intervention and expand our understanding of CAD prevention and treatment.

Supramolecular Recognition-Mediated Layer-by-Layer Self-Assembled Gold Nanoparticles for Customized Sensitivity in Paper-Based Strip Nanobiosensors.

Herein, a smart supramolecular self-assembly-mediated signal amplification strategy is developed on a paper-based nanobiosensor to achieve the sensitive and customized detection of biomarkers. The host-guest recognition between ß-cyclodextrin-coated gold nanoparticles (AuNPs) and 1-adamantane acetic acid or tetrakis(4-carboxyphenyl)porphyrin is designed and applied to the layer-by-layer self-assembly of AuNPs at the test area of the strip. Thus, the amplified platform exhibits a high sensitivity with a detection limit at subattogram levels (approximately dozens of molecules per strip) and a wide dynamic range of concentration over seven orders of magnitude. The applicability and universality of this sensitive platform are demonstrated in clinically significant ranges to measure carcinoembryonic antigen and HIV-1 capsid p24 antigen in spiked serum and clinical samples. The customized biomarker detection ability for the on-demand needs of clinicians is further verified through cycle incubation-mediated controllable self-assembly. Collectively, the supramolecular self-assembly amplification method is suitable as a universal point-of-care diagnostic tool and can be readily adapted as a platform technology for the sensitive assay of many different target analytes.

Integrated immunochromatographic assay for qualitative and quantitative detection of clenbuterol.

In this study, colloidal gold (CG) and time-resolved fluorescent nanobead (TRFN) probes were used to establish an integrated immunochromatographic assay (ICA) to qualitatively and quantitatively detect clenbuterol (CLE). The best experimental conditions for the two probes in separate ICAs were obtained by optimizing the antibody labeling concentration, the amount of antigen, and the concentration of probe. When the CG and TRFN probes co-existed in the ICA, the latter had no effect on the sensitivity of qualitative detection of the CG probe-based ICA. However, the CG probe optimized the linear range of quantitative detection in the TRFN probe-based ICA. The integrated test strip can be used for qualitative and quantitative detection of CLE in one step. When the amount of antigen reached 0.4 mg/mL, the CG probe concentration reached 1.2 µg/mL, and the TRFN probe concentration reached 0.68 µg/mL. The qualitative sensitivity of the integrated ICA was 0.5 ng/mL and its quantitative limit of detection was 0.04 ng/mL with a detection range of 0.1-2.7 ng/mL. This developed method is of great significance for large-scale samples screening and positive monitoring in the field of food safety testing.