ИСТИНА

Developing of the new methods of reliable, reagentless, sensitive, quick-response, real-time, and on-site microorganism detection systems is of great demand nowadays as an essential procedure for medical purposes, urban and industrial environmental control. Conventional microbiological methods are time-consuming and often require special sampling and pretreatment steps. Boronic acids are capable of selectively binding 1,2- or 1,3-diol moiety - structural part of saccharides. The latter are common parts of the microorganism’s cell wall. Amongst all sensitive to saccharides materials phenylboronic acid derivatives is the most promising one. In spite of considerable progress in area of saccharide sensors there are some limitations - low storage and operational stability, high cost, restricted mass production applications and complexity. Here we present impedimetric boronic acid substituted polyaniline-based reagentless sensor for diol-containing substances detection including microorganism’s cell wall groups. Optimized synthesis of poly (3-aminophenylboronic acid) results in polymer that increases it’s conductivity upon complexation with saccharides and hydroxyacids [1]. Such behavior resembles ‘self-doping’ phenomenon because of introducing additional charges into polymer chain upon specific binding. Other related systems demonstrate decrease of conductivity upon both specific and non-specific interactions [2]. The new polymer is able to distinguish between specific and non-specific binding by increasing or decreasing conductivity, respectively, yielding effective sensor material. We tested investigated system in detection of microorganism Penicillium chrysogenum. Polymer-modified interdigitated microelectrodes demonstrate conductivity increase upon interaction with microorganisms. We observed continuous increase of conductivity with increasing concentration of cells during experiments in liquid media and in bioaerosol from saturating suspensions. Limit of detection in liquid is approximately 500 CFU/ml and 20 000 CFU/ml of saturating liquid producing bioaerosol. Investigated polymer provides reagentless, sensitive and effective microorganism detection. The authors acknowledge the financial support from joint MSU-LGE lab. 1. E. A. Andreyev, M. A. Komkova, V. N. Nikitina et al. // Analytical Chemistry. — 2014. — Vol. 86, no. 23. — P. 11690–11695. 2. P. Qi, Y. Wan, D. Zhang // Biosensors and Bioelectronics. — 2013. — Vol. 39, no. 1. — P. 282–288