Specific Electrochemiluminescence of Aptamer‐Functionalized Quantum Dots with Lysozyme and Hemin as Co‐Triggers

Abstract

This work proposed a label-free, cost-effective and fairly sensitive electrogenerated chemiluminescence (ECL) strategy for the specific detection of lysozyme based on the hemin/G-quadruplex hybrid. Gold nanoparticles were spread onto the chitosan thin-film as substrate to adsorb thiolated captures: a hairpin-structured DNA, integrating dual head-tail connected functional domains: one aptamer sequence for lysozyme and the other for hemin (iron(III) proto-porphyrin IX). In the presence of the both, the hairpin conformation unfolded and transformed into the hemin/ G-quadruplex motif, which quenched the ECL emission of underlaid quantum dots significantly via the consumption of dissolved oxygen as endogenous coreactant. This construction enabled a wide linear response to lysozyme, ranging from 20 pg•mL 1 to 5 μg• mL 1 , with a detection limit as low as 4.95 pg• mL 1 (e.g. 9.4 pmol•L 1 ), demonstrating the prospective utilization of DNA technologies in bioanalysis.

Assembly of CdTe Quantum Dots and Photosystem II Multilayer Films with Enhanced Photocurrent

“…Owing to their remark-able features such as broad excitation range, narrow and symmetric emission, high photostability and high quantum yield, QDs have been applied in many fields from optoelectronics to biomedicine. [17][18][19][20][21][22] Most importantly, fluorescent QDs possess size-tunable emission covering the UV-blue to near infrared, which has overlap with the "red" light that can be efficiently captured by PSII. For example, both CdTe and CdSe QDs have been used in the investigation of energy transfer in the photosynthetic protein/semiconductor hybrid systems.…”