Comparison of fluorescence excitation modes for cdse semi-conductor quantum dots used in medical research

Kuzishchin  YA1, Martynov IL1, Osipov EV1, Samokhvalov PS2, Chistyakov AA1, Nabiev IR2
About authors

1 Department of Physics of Micro- and Nanosystems, National Research Nuclear University MEPhI, Moscow

2 Laboratory of Nano-Bioengineering, National Research Nuclear University MEPhI, Moscow

Correspondence should be addressed: Yuri A. Kuzishchin
Kashirskoe highway, 31, Moscow, 115409; moc.liamg@nihchsizuk.yiry

About paper

Funding: this work was supported by the Federal Target Program The National System for Chemical and Biological Security of the Russian Federation (2015– 2020) and carried out under the state contract No. K-27-НИР/146-2 dated December 28, 2015 signed by the Ministry of Healthcare of the Russian Federation and the National Research Nuclear University MEPhI.

Received: 2018-07-29 Accepted: 2018-08-25 Published online: 2018-10-09

Fluorescence spectroscopy is a powerful tool used in applied biological and medical research. Colloid semi-conductor quantum dots are promising fluorescent tags for simultaneous detection of different biopathogens. The techniques employing these tags can be improved by selecting the optimal modes for signal excitation and detection. The aim of the present work was to derive a mathematical expression to describe the signal-to-noise ratios in the pulsed and modulated excitation modes. Below, we compare these two modes of fluorescence excitation in ultralow quantities of quantum dots. We demonstrate that modulated excitation should be preferred for CdSe/ZnS quantum dots given that signal accumulation time is over 100 mc and the photosensor is exposed to background light of > 1 μW.

Keywords: quantum dots, CdSe/ZnS, luminescence, excitation, photodetection