A Quick and Parallel Analytical Method Based on Quantum Dots Labeling for ToRCH-Related Antibodies

Abstract

Quantum dot is a special kind of nanomaterial composed of periodic groups of II–VI, III–V or IV–VI materials. Their high quantum yield, broad absorption with narrow photoluminescence spectra and high resistance to photobleaching, make them become a promising labeling substance in biological analysis. Here, we report a quick and parallel analytical method based on quantum dots for ToRCH-related antibodies including Toxoplasma gondii, Rubella virus, Cytomegalovirus and Herpes simplex virus type 1 (HSV1) and 2 (HSV2). Firstly, we fabricated the microarrays with the five kinds of ToRCH-related antigens and used CdTe quantum dots to label secondary antibody and then analyzed 100 specimens of randomly selected clinical sera from obstetric outpatients. The currently prevalent enzyme-linked immunosorbent assay (ELISA) kits were considered as “golden standard” for comparison. The results show that the quantum dots labeling-based ToRCH microarrays have comparable sensitivity and specificity with ELISA. Besides, the microarrays hold distinct advantages over ELISA test format in detection time, cost, operation and signal stability. Validated by the clinical assay, our quantum dots-based ToRCH microarrays have great potential in the detection of ToRCH-related pathogens.

Simultaneous Detection of Multi-DNAs and Antigens Based on Self-Assembly of Quantum Dots and Carbon Nanotubes

“…For applications in biomedical studies, QDs should be water soluble, which can be achieved in two ways: the first is to directly synthesize QDs in aqueous solution; the other is to synthesize QDs in organic solvents and then transfer the hydrophobic QDs into aqueous solution, for example, by ligand exchange or polymer coating . So far, several methods have been developed to synthesize water-soluble quantum dots for use in cellular imaging, immunoassays, DNA hybridization and optical bar-coding (Drbohlavova et al, 2009;Yang et al, 2009). Moreover, QDs also have been used to study the interaction between protein molecules or detect the dynamic course of signal transduction in live cells by fluorescence resonance energy transfer (FRET) (Chan and Nie, 1998).…”

“…QDs and primary amines (-NH 2 ) on intact antibodies using EDAC as a catalyst; (c) sitedirected conjugation via oxidized carbohydrate groups on the antibody Fc portion and covalent reactions with hydrazide-modified QDs; (d) conjugation of histidine-tagged peptides or antibodies to Ni-NTA modified QDs; and (e) noncovalent conjugation of streptavidincoated QDs to biotinylated antibodies (Xing et al, 2007). (With permission from Nature) Recently, our group have reported a quick and parallel analytical method based on QDs for ToRCH-related antibodies including Toxoplasma gondii, Rubella virus, Cytomegalovirus and Herpes simplex virus type 1 (HSV1) and 2 (HSV2) (Yang et al, 2009). We fabricated the microarrays with the five kinds of ToRCH-related antigens and used CdTe QDs to label secondary antibody and then analyzed 100 specimens of randomly selected clinical sera from obstetric outpatients (Fig.…”

The Application of Lateral Flow Immunoassay in Point of Care Testing: A Review

“…At present, fluorescent lateral flow test strips (LFTSs) are undergoing accelerated development, where the intensity of the response can be detected quantitatively using appropriate test equipment. LFIA based on enzymecatalyzed chemiluminescence detection has been used for analyzing trinitrotoluene in forensic and environmental applications [5], as well as for detecting Cry1Ab with an amplifier signal value [6]. LFIA based on quantum dots (QDs) has been developed for the detection of tumor markers [7,8], mercury ions (Hu et al 2014), avian influenza virus [9], pesticides and nerve agents [10].…”

Real time PCR based on Fluorescent Quenching of Mercaptoacetic Acid-Modified CdTe Quantum Dots for Ultrasensitive Specific Detection of Nucleic Acids

“…For example, quantum dots have been used successfully in cellular imaging [3][4][5], immunoassays [6], ultrasensitive DNA and antigen detection [7][8], and optical barcoding [9]. Quantum dots also have been used to study the interaction between protein molecules or detect the dynamic course of signal transduction in live cells by Fluorescence Resonance Energy Transfer(FRET) [10][11].…”