Quantification of cardiovascular disease biomarkers via functionalized magnetic beads and on-demand detachable quantum dots

Abstract

Cardiovascular disease (CVD) is a potent cause of mortality in both advanced and developing countries. While soluble CD40L (sCD40L) has been implicated as a correlative factor among CVD patients, methods to quantify sCD40L are not yet well-established. In this paper, we present an ability to separate and quantify sCD40L via a simple immunomagnetic assay. Composed of functionalized magnetic beads conferred with directionality and on-demand detachable quantum dots for subsequent optical analysis, our system utilizes the competitive nature of imidazole and nickel ions for histidine. In essence, we demonstrate the capacity to effectively separate and detect sCD40L within a clinically relevant range that contains the cut-off value for acute coronary disease. While sCD40L was used to conduct this study, we envision the use of our system for the separation and quantification of other biomarkers.

The Roles of Nanoparticles in Stem Cell-Based Therapy for Cardiovascular Disease

“…Because of their unique optical properties (broad excitation and narrow emission spectra), they emit brighter and particularly stable fluorescence (Michalet et al, 2005). A previous study presented an immunomagnetic assay based on functionalized magnetic beads and detachable QDs for the separation and quantication of soluble CD40 Ligand (CD40 Ligand, also known as tumor necrosis factor associated activation protein, is related to atherosclerosis) from solution (Park et al, 2013). Recently, a study firstly reported that 0D titanium carbide MXene QDs could be incorporated into a chitosan-based hydrogel to create a 3D platform with enhanced physicochemical properties for stem cell delivery and tissue repair (Rafieerad et al, 2019).…”

Multiplexed Nanobiosensors: Current Trends in Early Diagnostics

“…Magnetic bead-quantum dot assay is a similar detection method, except instead of organic dyes, quantum dots are used (Figure 3). There are several articles that have established magnetic bead-quantum dot assays to detect one specific analyte [20,[26][27][28]. The most sensitive method using a magnetic bead-quantum dot sandwich assay for the capture and detection of human S100B protein (most extensively studied biomarker for mild traumatic brain injury) in serum was demonstrated by Kim et al in 2015 [20].…”

Magnetic bead-quantum dot assay for detection of a biomarker for traumatic brain injury

“…Elution is a commonly used method for protein purification and immunoprecipitation, and enhanced detection resolution of the MB-QD sandwich assay has been reported following elution using imidazole and urea (see ESI, Table S1 †). 12,[24][25][26][27][28][29][30][31][32] For the MB-Ab-S100B-Ab-QD conjugates, the fluorescence signal for detection of 3 ng of protein is 20% above the background (control) signal (Fig. 4C).…”

“…22,23 Recently, surface functionalized QDs in conjunction with magnetic beads have been used to label captured analytes through antibody-analyte binding as signal transduction probes. 12,[24][25][26][27][28][29][30][31][32] Here we report on a magnetic bead-quantum dot (MB-QD) sandwich assay for capture and detection of S100B in serum (Fig. 1).…”