On-chip magneto-immunoassay for Alzheimer's biomarker electrochemical detection by using quantum dots as labels

• Published in: Biosensors & bioelectronics 2014-04, Vol.54, p.279-284
• Main Authors: Medina-Sánchez, Mariana, Miserere, Sandrine, Morales-Narváez, Eden, Merkoçi, Arben
• Format: Article
• Language: English
• Subjects: Alzheimer biomarker; Alzheimer Disease - blood; Alzheimer's disease; Alzheimer, Malaltia d; Apolipoprotein E (ApoE); Apolipoproteins E - blood; Biochemical markers; Biological and medical sciences; Biosensing Techniques - instrumentation; Biotechnology; Cadmium Compounds - chemistry; Electrochemical Techniques - instrumentation; Electrochemistry; Electroquímica; Enginyeria electrònica; Equipment Design; Fundamental and applied biological sciences. Psychology; Humans; Immunoassay - instrumentation; Limit of Detection; Magnetic beads; Microfluidic; Microfluidic Analytical Techniques - instrumentation; Quantum dots; Quantum Dots - chemistry; Selenium Compounds - chemistry; Sulfides - chemistry; Zinc Compounds - chemistry; Àrees temàtiques de la UPC
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2013.10.069

Electrochemical detection of cadmium-selenide/zinc-sulfide (CdSe@ZnS) quantum dots (QDs) as labeling carriers in an assay for apolipoprotein E (ApoE) detection has been evaluated. The immunocomplex was performed by using tosylactivated magnetic beads as preconcentration platform into a flexible hybrid polydimethylsiloxane (PDMS)-polycarbonate (PC) microfluidic chip with integrated screen printed electrodes (SPE). All the immunoassay was performed in chip and in flow mode. The sensitive electrochemical detection was obtained by square wave anodic stripping voltammetry. ApoE was evaluated for its potential as biomarker for Alzheimer's disease detection, achieving a limit of detection (LOD) of ~12.5ngmL−1 with a linear range from 10 to 200ngmL−1 and high accuracy for diluted human plasma. •We report the development of a microfluidic platform for Alzheimer's biomarker determination.•We used quantum dots as electrochemical labels and magnetic beads as preconcentration platform.•Very low limit of detection for this kind of sample of 12.5ngmL−1 and uses of few microliters volume of sample.•Immunoassay performance in relatively short time (2h) and detection in 3min.