Biosensors

The principle of detection of certain DNA sequences using beacons is based on hybridization of a phosphor-containing bioassay with a target, followed by luminescence of the complex.

Since luminescence is capable of detecting single molecules in solution, this technique is very sensitive. We are developing such probes for the detection of various analytes based on luminescent metal clusters (link to the metal clusters tab). In Fig. 1 shows a model of such a ligh-up luminescent sensor based on a DNA-stabilized silver cluster for the detection of micro-RNA:

Fig. 1. Left DNA strand - DNA_left (blue), right DNA strand - DNA_right (red), silver ions (green), target - microRNA analog (brown) (CTG TGC GTG TGA CAG CGG CTG A), spacer (gray)

When the two halves of the sensor hybridize with the target, a bright luminescent DNA-stabilized silver cluster is formed. More details about the mechanism of operation of these sensors can be found in our recent work: Reveguk Z.V., Pomogaev V.A., Kapitonova M.A., Buglak A.A., Kononov A.I. Structure and Formation of Luminescent Centers in Light-up Ag Cluster-Based DNA Probes, J. Phys. Chem. C. 2021, 125, 6, 3542–3552 [DOI] .

We have proposed the synthesis of complexes of metal clusters with immunoglobulins, proteins that are part of the blood serum along with albumin and are responsible for the state of the body's immune system (Fig. 2).

Fig. 2. Structures of the main proteins of human blood serum: albumin (left) and immunoglobulin G (right).

This made it possible to propose an express method, which is being finalized at the present time, to determine the level of these proteins in human blood for the diagnosis of diseases (Sych TS, Polyanichko AM, Plotnikova LV, Kononov AI, Luminescent silver nanoclusters in probing immunoglobulins and serum albumins in protein mixtures, Anal. Methods, 2019, 11, 6153-6158 [DOI] ) .