TY - JOUR A1 - Cywinski, Piotr J. A1 - Moro, Artur J. A1 - Ritschel, Thomas A1 - Hildebrandt, Niko A1 - Löhmannsröben, Hans-Gerd T1 - Sensitive and selective fluorescence detection of guanosine nucleotides by nanoparticles conjugated with a naphthyridine receptor JF - Analytical & bioanalytical chemistry N2 - Novel fluorescent nanosensors, based on a naphthyridine receptor, have been developed for the detection of guanosine nucleotides, and both their sensitivity and selectivity to various nucleotides were evaluated. The nanosensors were constructed from polystyrene nanoparticles functionalized by (N-(7-((3-aminophenyl) ethynyl)-1,8-naphthyridin- 2-yl) acetamide) via carbodiimide ester activation. We show that this naphthyridine nanosensor binds guanosine nucleotides preferentially over adenine, cytosine, and thymidine nucleotides. Upon interaction with nucleotides, the fluorescence of the nanosensor is gradually quenched yielding Stern-Volmer constants in the range of 2.1 to 35.9mM(-1). For all the studied quenchers, limits of detection (LOD) and tolerance levels for the nanosensors were also determined. The lowest (3 sigma) LOD was found for guanosine 3',5'-cyclic monophosphate (cGMP) and it was as low as 150 ng/ml. In addition, we demonstrated that the spatial arrangement of bound analytes on the nanosensors' surfaces is what is responsible for their selectivity to different guanosine nucleotides. We found a correlation between the changes of the fluorescence signal and the number of phosphate groups of a nucleotide. Results of molecular modeling and zeta-potential measurements confirm that the arrangement of analytes on the surface provides for the selectivity of the nanosensors. These fluorescent nanosensors have the potential to be applied in multi-analyte, array-based detection platforms, as well as in multiplexed microfluidic systems. KW - Naphthyridine receptor KW - cGMP KW - Base pairing KW - Nucleotide nanosensor KW - Fluorescence spectroscopy Y1 - 2011 U6 - https://doi.org/10.1007/s00216-010-4420-2 SN - 1618-2642 VL - 399 IS - 3 SP - 1215 EP - 1222 PB - Springer CY - Heidelberg ER -