Luminescent sensors for detection of pterin and its analogues based on amino-acid stabilized gold clusters

Abstract

Pteridines are important low molecular weight biomarkers used in the diagnostics of inflammation, oxidative stress, phenylketonuria, cancer, etc. In this experimental work we present a simple and selective approach to determine pteridines (pterin, leucopterin and folic acid) and nucleobase guanine concentration using luminescent gold clusters stabilized by aromatic amino acids. We synthesized several new gold clusters (AA-Au NCs) stabilized by 3,4-dihydroxy-L-phenylalanine, L-tryptophan, L-tyrosine and L-phenylalanine, emitting in the violet-green spectral range. The choice of amino acids as stabilizing matrices is primarily due to their high biocompatibility (in the context of potential in vivo applications). In addition, the small size of amino acid molecules has a positive effect on the efficiency and homogeneity of cluster synthesis. Obtained clusters were applied to the in vitro determination of pterin, leucopterin, folic acid and guanine depending on the stabilizing matrix. AA-Au NC-based sensors work according to "turn-on" and "turn-off" mechanism. Thus, a facile and cost-effective approach for the detection of pteridines is proposed. We have also tested the performance of sensors for pterine and folic acid under serum conditions. The obtained results indicate that the sensor functionality is preserved, but the limit of detection values are slightly deteriorated due to the effects of serum proteins on the sensory systems. This work was supported by the Russian Science Foundation grant 20-73-10029.

Speaker

Sych Tomash
Department of Molecular Biophysics and Polymer Physics, Physical faculty, St Petersburg University, Saint-Petersburg, Russia
Russia

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