Label-free quantum dot conjugates for human protein IL-2 based on molecularly imprinted polymers

• Type: Article in International Scientific Journal
• Date: 2020

Authors

Piloto, AML (Author) Other; Ribeiro, DSM (Author) Other; Rodrigues, SSM (Author) Other; Joao L M Santos (Author) FFUP; Ferreira Sales, MGF (Author) Other

Journal

Title: Sensors and Actuators, B: Chemical

Vol. 304

ISSN: 0925-4005

Publisher: Elsevier

Indexing

ISI Web of Knowledge - 0 Citations

Scopus - 7 Citations

Other information

Authenticus ID: P-00R-EA4

DOI: 10.1016/j.snb.2019.127343

Abstract (EN): Herein, the development of a fluorescent-based sensor by combining quantum dots (QDs) with molecularlyimprinted technology (MIT), intensively optimized to generate exceptional operating features is presented. This sensor is designed to target human interleukin-2 (IL-2) in synthetic human serum. IL-2 is a regulatory protein released as a triggered response from the immune system towards an inflammation. For this purpose, cadmium telluride (CdTe) QDs are prepared with 3-mercaptopropionic acid (MPA) and modified afterwards to produce an IL-2 imprinted polymer with methacrylic acid and N,N '-methylenebis(acrylamide), upon removal of the template under optimized conditions. During IL-2 rebinding, the fluorescence intensity of CdTe@MPA QDs is quenched in a concentration dependent manner. Using surface imprinting technology, the optimal fluorescence signals yielded a linear response versus logarithm of IL-2 concentration from 35 fg/ml to 39 pg/ml, in a 1000-fold diluted synthetic human serum. The limit of detection obtained is 5.91 fg/ml, lying below the concentration levels of IL-2 with clinical interest for cancer diagnosis (9.4-19.2 pg/ml). Overall, the method presented herein is a demonstration that the combination of MIP and QDs for protein detection constitutes a powerful tool in clinical analysis, providing low cost, sensitive and quick responses. The same concept may be further extended to other proteins of interest.

Language: English

Type (Professor's evaluation): Scientific

No. of pages: 12