Sensitive and selective fluorescence detection of guanosine nucleotides by nanoparticles conjugated with a naphthyridine receptor.
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 35.9 mM(-1). For all the studied quenchers, limits of detection (LOD) and tolerance levels for the nanosensors were also determined. The lowest (3σ) 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 ζ-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.
Department of Physical Chemistry, Institute of Chemistry, University of Potsdam, Karl-Liebknecht-Str. 24-25, Golm, 14476 Potsdam, Germany. piotr.cywinski@uni-potsdam.de
Piotr J
PJ
Cywinski
Artur J
AJ
Moro
Thomas
T
Ritschel
Niko
N
Hildebrandt
Hans-Gerd
HG
Löhmannsröben
D005453:Fluorescence; D006151:Guanosine / Q000032:analysis*; D053758:Nanoparticles / Q000737:chemistry*; D036103:Nanotechnology; D009287:Naphthyridines / Q000138:chemical synthesis / Q000737:chemistry*; D009711:Nucleotides / Q000032:analysis*; D011137:Polystyrenes / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D013499:Surface Properties
D009287:Naphthyridines; D009711:Nucleotides; D011137:Polystyrenes; D006151:Guanosine