M. Dabrowski, P. Sindhu Sharma, Z. Iskierko, K. Noworyta, M. Cieplak, S. Oborska, A. Kuhn, W. Kutner

Biosensors and Bioelectronics, 2016, 79, 627-635.

An elevated concentration of D-arabitol in urine, especially compared to that of L-arabitol or creatinine, is indicative of a fungal infection. For that purpose, we devised, fabricated, and tested chemical sensors determining D-arabitol. These chemosensors comprised the quartz crystal resonator (QCR) or extended-gate field-effect transistor (EG-FET) transducers integrated with molecularly imprinted polymer (MIP) film recognition units. To this end, we successfully applied a covalent approach to molecular imprinting, which involved formation of weak reversible covalent bonds between vicinal diols of arabitol and boronic acid substituents of the bithiophene functional monomer used. The MIP films were synthesized and simultaneously deposited on gold electrodes of quartz crystal resonators (Au-QCRs) or Au-glass slides by potentiodynamic electropolymerization. With the QCR and EG-FET chemosensors, the D-arabitol concentration was determined under flow-injection analysis and stagnant-solution binding conditions, respectively. Selectivity with respect to common interferences, and L-arabitol in particular, of the devised chemosensors and their limits of detection were lower than the D-arabitol concentrations in urine of patients with invasive candidiasis (>220 μM). Therefore, the devised chemosensors are suitable for early diagnosis of fungal infections caused by Candida sp. yeasts.