TY - JOUR
T1 - An effective nanosensor for organic molecules based on water-soluble mercaptopropionic acidcapped CdTe nanocrystals with potential application in high-throughput screening and high-resolution optical microscopy
AU - Lau, Pick Chung
AU - Norwood, Robert A.
AU - Mansuripur, Masud
AU - Peyghambarian, Nasser
PY - 2014/6/1
Y1 - 2014/6/1
N2 - Specially-treated glass substrates coated with a thin film of water soluble mercaptopropionic acid (MPA) capped CdTe nanocrystals (NCs) were prepared and found to undergo photoluminescence changes by as much as 40% when micro-droplets of organic molecules were placed in the nanometer-range proximity of the NCs. This imaging technique involving close proximity between a nano-crystal and an organic molecule is found to provide a 2 × -3 × enhanced contrast ratio over the conventional method of fluorescence imaging. Photoluminescence of NCs is recoverable upon removal of the organic molecules, therefore validating these NCs as potential all-optical organic molecular nanosensors. Upon optimization and with proper instrumentation, these nano-crystals could eventually serve as point-detectors for purposes of super-resolution optical microscopy. No solvents are required for the proposed sensing mechanism since all solutions were dried under argon flow. Fluorophores and fluorescent proteins were investigated, including fluorescein, Rhodamine 6G, and green fluorescent protein (GFP). Furthermore, NC photoluminescence changes were systematically quantified as a function of the solution pH and of the organic molecule concentration. Long duration (> 40 minutes) continuous excitation studies were conducted in order to evaluate the reliability of the proposed sensing scheme.
AB - Specially-treated glass substrates coated with a thin film of water soluble mercaptopropionic acid (MPA) capped CdTe nanocrystals (NCs) were prepared and found to undergo photoluminescence changes by as much as 40% when micro-droplets of organic molecules were placed in the nanometer-range proximity of the NCs. This imaging technique involving close proximity between a nano-crystal and an organic molecule is found to provide a 2 × -3 × enhanced contrast ratio over the conventional method of fluorescence imaging. Photoluminescence of NCs is recoverable upon removal of the organic molecules, therefore validating these NCs as potential all-optical organic molecular nanosensors. Upon optimization and with proper instrumentation, these nano-crystals could eventually serve as point-detectors for purposes of super-resolution optical microscopy. No solvents are required for the proposed sensing mechanism since all solutions were dried under argon flow. Fluorophores and fluorescent proteins were investigated, including fluorescein, Rhodamine 6G, and green fluorescent protein (GFP). Furthermore, NC photoluminescence changes were systematically quantified as a function of the solution pH and of the organic molecule concentration. Long duration (> 40 minutes) continuous excitation studies were conducted in order to evaluate the reliability of the proposed sensing scheme.
UR - http://www.scopus.com/inward/record.url?scp=84903731740&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84903731740&partnerID=8YFLogxK
U2 - 10.1364/BOE.5.002420
DO - 10.1364/BOE.5.002420
M3 - Article
AN - SCOPUS:84903731740
SN - 2156-7085
VL - 5
SP - 2420
EP - 2434
JO - Biomedical Optics Express
JF - Biomedical Optics Express
IS - 7
ER -