Establishment of a R-Sphere labelled immunoassay platform and its rapid combined quantitative detection of ketamine and morphine in serum.

Background And Aims: Ketamine and morphine are among the most commonly abused drugs. Ketamine is classified as a new psychoactive substance, while morphine represents the opioid class. These two substances may exhibit synergistic or antagonistic effects in their pharmacological actions, and their combined abuse could lead to more severe health risks, such as respiratory depression.

Establishment of a Raman microsphere-based immunochromatographic method for the combined detection of influenza A and B viruses and SARS-CoV-2 antigen on a single T-line.

A simple and rapid method based on Raman microsphere immunochromatography was developed in this study for the simultaneous detection of influenza A and B viruses and SARS-CoV-2 on a single test T-line. Three types of Raman microspheres with different Raman characteristics were used as the signal sources and were labelled with monoclonal antibodies against FluA, FluB and SARS-CoV-2, respectively. A mixture of antibodies containing anti-FluA monoclonal antibody, anti-FluB monoclonal antibody and anti-SARS-CoV-2 was sprayed on the detection line (T), and goat polyclonal antibody to chicken (IgY) encapsulated on the quality control line (C), for qualitative detection of these three viruses by the double antibody sandwich method.

Development of a system for detecting cardiac troponin I by background fluorescence quenching based on internal filtration effect.

The present study sought to develop a cardiac troponin I (cTnI) detection system based on background fluorescence quenching of internal filtration effect (IFE) and study the influence of IFE on the sensitivity of cTnI detection. Three nanogold materials were synthesized as fluorescence quenchers, and rhodamine 6 G (R6G) and Cy5 were used as fluorescence probes. Six experimental systems were established to detect cTnI in negative serum test solutions and clinical serum samples.

Combined detection of SARS-CoV-2 neutralizing antibodies and specific IgG in plasma based on SERS magnetic sensor.

In this study, a surface-enhanced Raman spectroscopy (SERS) magnetic sensor is established based on SERS principle and magnetic separation technology, and a highly sensitive, simple and fast method for quantitative detection of neutralizing antibodies (nABs) and specific IgG of SARS-CoV-2 in plasma is established combined with immunoassay. Two kinds of Raman nanospheres (RNPs) with different characteristic Raman shifts are used as signal sources and coupled to ACE2 and anti-IgG (FC) antibodies respectively, and magnetic beads are coupled to RBD. The competitive relationship between ACE2 and nABs, the binding relationship between specific IgG and anti-IgG (FC) antibodies are determined.

Study on the performance of novel nanomaterials for detection of biomarkers such as PCT based on immunochromatography sensitivity.

In this study, by comparing the UV-vis spectral characteristics of colloidal gold and colloidal gold enhancer, and their differences as immunochromatographic tracers in the qualitative detection of PCT, IL-6, Hp and quantitative determination of PCT performance, the factors that may affect the sensitivity were discussed. The results show that the absorbance at 520 nm of CGE diluted 20-fold and colloidal gold diluted 2-fold were comparable, and the sensitivity of CGE immunoprobe for qualitative detection of PCT, IL-6 and Hp was higher than that of colloidal gold immunoprobe, and the reproducibility and accuracy of both immunoprobes for quantitative detection of PCT were good. Indicating that the high sensitivity of CGE immunoprobe detection is mainly due to the absorption coefficient of CGE at 520 nm is about 10 times that of colloidal gold immunoprobe, CGE has stronger light absorption capacity and stronger quenching effect on rhodamine 6 G on the nitrocellulose membrane surface of the test strip.

Rapid and sensitive detection of amphetamine by SERS-based competitive immunoassay coupled with magnetic separation.

Amphetamine (AMP), as a psychiatric drug acting on the central nervous system, and has become one of the most common drugs of abuse in the illegal market at present, which adversely affects social public safety. We developed a SERS magnetic immunoassay with high sensitivity, specificity, and rapid and quantitative detection of AMP. We synthesized a high SERS intensity substrate (Au-XP013@Ag) using the "hot spot" effect and combined it with antibodies to form SERS immunotags (Au-XP013@Ag-AMP-mAb).

Synchronous detection of IgG subtypes based on SERS combined with immunoassay.

In this study, a rapid, simple, highly sensitive and anti-interference method for the joint detection of four IgG subtypes is established by using Raman microspheres with four characteristic Raman spectra. The results show that the concentrations of IgG1 in the range of 0-1500 ng ml, IgG2 in the range of 0-1100 ng ml, IgG3 in the range of 0-88.7 ng ml, IgG4 in the range of 0-77.

SERS-based magnetic immunoassay for simultaneous detection of cTnI and H-FABP using core-shell nanotags.

Acute myocardial infarction (AMI) is the single leading cause of worldwide mortality and morbidity. Heart-type fatty acid-binding protein (H-FABP) and cardiac troponin I (cTnI), as biomarkers emerging at different stages of AMI, have complementary advantages in terms of specificity and sensitivity. Therefore, we developed a magnetic immunoassay method based on surface-enhanced Raman scattering (SERS) to detect H-FABP and cTnI simultaneously.

A novel surface-enhanced Raman scattering method for simultaneous detection of ketamine and amphetamine.

As common psychotropic drugs, ketamine (KET) and amphetamine (AMP) are often consumed by drug users at the same time, which seriously threatens people's health. Therefore, the study of simultaneous detection methods for KET and AMP is imperative. In this study, a novel method for the simultaneous detection of KET and AMP in serum was established on the basis of surface-enhanced Raman scattering (SERS).

Detection of H-FABPA by novel SERS combined with magnetic reaction.

The purpose of this paper is to establish a method for easy operation, high sensitivity, strong anti-interference ability, and rapid quantitative detection of cardiac fatty acid-binding protein in acute myocardial infarction biomarkers, so that it can be quickly diagnosed at an early stage and provide a basis for further treatment. Based on the SERS principle, the traditional sandwich system generated by the reaction was captured by the streptavidin (SA) magnetic beads through the specific reaction of SA and biotin then enriched by the applied magnetic field. The enriched magnetic beads are subjected to Raman detection to achieve a process of quantitative detection of the antigen.

Development of a Quantitative Detection Card for Heart-type Fatty Acid-binding Protein based on Background Fluorescence Quenching Immune Chromatography.

Background: To establish a fast and simple quantitative method for detection of heart-type fatty acid-binding protein (H-FABP) in serum based on a background fluorescence quenching immunochromatographic assay.

Methods: A detection card based on the double-antibody sandwich double-antibody method with background fluorescence quenching was developed for quantitative measurement of H-FABP in serum. The optimal concentrations of control for coating the test and control lines were determined as well as the concentrations of gold-labeled antibodies used in preparing the detection system.

Determination of Aflatoxin M1 and Chloramphenicol in Milk Based on Background Fluorescence Quenching Immunochromatographic Assay.

Harsh demanding has been exposed on the concentration of aflatoxin M1 (AFM1) and chloramphenicol (CAP) in milk. In this study, we developed a new method based on background fluorescence quenching immunochromatographic assay (bFQICA) to detect AFM1 and CAP in milk. The detection limit for AFM1 was 0.

Antigen detection based on background fluorescence quenching immunochromatographic assay.

Gold immunochromatographic assay (GICA) has been around for quite a while, but it is qualitative in the vast majority of applications. A fast, simple and quantitative GICA is in call for better medicine. In the current study, we have established a novel, quantitative GICA based on fluorescence quenching and nitrocellulose membrane background signals, called background fluorescence quenching immunochromatographic assay (bFQICA).

Evaluation of a method for the simultaneous detection of multiple tumor markers using a multiplex suspension bead array.

Objective: To achieve higher tumor detection efficiency, we evaluated a multiplex assay for TM analysis based on the Luminex-100 multiplex suspension bead array.

Design: The assay simultaneously determined the concentrations of nine TMs in 1114 human serum specimens (546 patients with tumors, 158 patients with non-tumor inflammatory diseases, and 410 normal controls). The nine TMs were AFP, CEA, CA125, CYFRA 21-1, CA242, f-PSA, t-PSA, NSE and free β-hCG.