TY  - JOUR
A1  - Lapresta-Fernández, Alejandro
A1  - Cywinski, Piotr J.
A1  - Moro, Artur J.
A1  - Mohr, Gerhard J.
T1  - Fluorescent polyacrylamide nanoparticles for naproxen recognition
N2  - We present the synthesis of fluorescent acrylamide nanoparticles (FANs) capable of recognizing non-steroidal anti-inflammatory drugs (NSAIDs) in buffered aqueous solutions. Within this important group, we selected naproxen, one of the 2-arylpropionic acids (profens), due to its use for the treatment of moderate pain, fever, and inflammation. The nanosensors were prepared under mild conditions of inverse microemulsion polymerization using aqueous acrylamide as the monomer and N,N'-methylenebisacrylamide as the crosslinker, employing the surfactants polyoxyethylene-4-lauryl ether (Brij (R) 30) and sodium bis(2-ethylhexyl) sulfosuccinate in hexane. Furthermore, a fluorescent monomer, (E)-4-[4- (dimethylamino)styryl]-1-[4-(methacryloyloxymethyl)benzyl]pyridinium chloride (mDMASP) has been synthesized and incorporated into the nanoparticles. The nanosensors exhibit a broad absorbance at around 460 nm and a structureless fluorescence band with maximum at 590 nm in 0.5 M phosphate buffer (pH=7.2). The recognition process is performed on the basis of ionic interactions which are monitored by the fluorescence increase at 590 nm upon addition of different concentrations of naproxen. The FANs show a size distribution in the range of 20-80 nm, with a hydrodynamic diameter of 34 nm. In order to assess the selectivity of the FANs, a systematic study was conducted on the effect produced by drugs and biomolecules that could interfere with the analysis of naproxen.
Y1  - 2009
UR  - http://www.springerlink.com/content/100417
U6  - https://doi.org/10.1007/s00216-009-3007-2
SN  - 1618-2642
ER  - 
TY  - JOUR
A1  - Cywinski, Piotr J.
A1  - Moro, Artur J.
A1  - Löhmannsröben, Hans-Gerd
T1  - Cyclic GMP recognition using ratiometric QD-fluorophore conjugate nanosensors
JF  - Biosensors and bioelectronics : the principal international journal devoted to research, design development and application of biosensors and bioelectronics
KW  - Quantum dots
KW  - Naphthyridines
KW  - Cyclic GMP
KW  - Base pairing
KW  - Fluorescent nanoconjugate
KW  - Nanosensor
Y1  - 2014
U6  - https://doi.org/10.1016/j.bios.2013.09.002
SN  - 0956-5663
SN  - 1873-4235
VL  - 52
SP  - 288
EP  - 292
PB  - Elsevier
CY  - Oxford
ER  - 
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  -