Florida International University

Haixiang Yu

Yi Xiao

Yingzhu Liu

Weijuan Yang

Yingping Luo

Juan Canoura

Xiaowen Xu

Obtin Alkhamis

Pingping Liang

Daniel Roncancio

The subject invention provides materials and methods for single-step detection of target molecules in a sample. The methods and assays of the subject invention employ a dye-displacement strategy, in which aptamers complexed with a cyanine dye for sensitive and rapid detection of targets of interest. In the presence of a target, aptamer-target binding liberates the non-covalently bound aptamer-binding dye, resulting in optical changes that can be observed spectrophotometrically or with the naked eye. The methods and assays of the subject invention enable the colorimetric detection of targets of interest regardless of their structure, sequence, target-binding affinity, and physicochemical properties of their targets.

DNA aptamer-cyanine complexes as mephedrone and cannabinoid colorimetric sensors

The subject invention provides methods, assays, and products for detecting small-molecule targets in a complex sample in both clinical and field settings. The subject invention provides aptamer-based sensors and methods of use thereof. The subject invention provides exonuclease-based methods for generating structure-switching aptamers from fully folded or pre-folded aptamers and developing aptamer-based sensors for small-molecule detection. The method for detecting one or more small-molecule targets in a sample comprises contacting the sample with one or more aptamer-based sensor selective for each of the small-molecule targets, and detecting the small-molecule target in the sample.

Methods for generating structure-switching aptamers and uses thereof

The subject invention provides a SELEX strategy for isolating cross-reactive aptamers that recognize a core structure of a small-molecule family and bind to several structurally-similar molecules in the family. The subject invention also provides methods, assays, and products for detecting small-molecule targets of the family in a sample in both clinical and field settings. Such method is based on an aptamer sensor that reports the presence of small-molecule targets via a sensitive colorimetric signal for naked-eye detection. The subject invention further provides exonuclease-based methods for generating structure-switching aptamers from fully folded aptamers and developing electrochemical aptamer-based (E-AB) sensors for rapid and sensitive detection of synthetic cathinones.

Method for isolating cross-reactive aptamer and use thereof

The subject invention provides methods, assays, and products for visual detection of small-molecule targets in a sample in both clinical and field settings within minutes. The subject invention is based on an aptamer sensor that reports the presence of small-molecule target via a sensitive colorimetric signal for naked-eye detection. The aptamer sensor is a CBSAzyme-based sensor having both target-mediated cooperative behavior of the CBSA and peroxidase-mimicking catalytic activity of DNAzyme. The subject invention also provides methods of using the CBSAzyme-based sensor.

Material and method for colorimetric detection of small-molecule targets

The subject invention provides materials and methods for single-step detection of small molecules, e.g., natural and synthetic cannabinoids, in a sample. The subjection invention provides nucleic acids materials, e.g., aptamers (nucleic acid oligonucleotides) that can bind to natural and/or synthetic cannabinoids. The method for detecting a natural or synthetic cannabinoid in a sample comprises contacting the sample with an aptamer-based sensor selective for the natural or synthetic cannabinoid, and sensitively and rapidly detecting the natural or synthetic cannabinoid in the sample. The aptamer-based sensor comprises aptamers that can specifically binds to natural and/or synthetic cannabinoids with nanomolar dissociation constant.

Aptamers that bind to natural and synthetic cannabinoids

The subject invention provides a SELEX strategy for isolating cross-reactive aptamers that recognize a core structure of a small-molecule family and bind to each several structurally-similar molecules in the family. The subject invention also provides methods, assays, and products for detecting small-molecule targets of the family in a sample in both clinical and field settings. Such method is based on an aptamer sensor that reports the presence of small-molecule targets via a sensitive colorimetric signal for naked-eye detection. The subject invention further provides exonuclease-based methods for generating structure-switching aptamers from fully folded aptamers and developing electrochemical aptamer-based (E-AB) sensors for rapid and sensitive detection of synthetic cathinones.

The subject invention provides methods, assays, and products for detecting small molecules in a sample, in particular, in both clinical and field settings. The method for detecting a small-molecule target, preferably, a synthetic cathinone in a sample comprises contacting the sample with an aptamer-based sensor selective for the small-molecule target, and detecting the small-molecule target in the sample. Specifically, the method utilizes an aptamer-based sensor comprising a dye binding to a three-way junction binding domain of an aptamer. Binding of small-molecule target to the aptamer displaces the dye, generating a spectroscopic signal that can be used for detection of the small-molecule target and quantitative measurement of the target concentration.

Materials and methods for rapid and specific detection of synthetic cathinones

The subject invention provides a novel SELEX strategy for isolating cross-reactive aptamers that recognize a core structure of a small-molecule family and bind to each structurally-similar molecule in said family. The subject invention also provides methods, assays, and products for detecting small-molecule targets of the family in a sample in both clinical and field settings. Such method is based on an aptamer sensor that reports the presence of small-molecule targets via a sensitive colorimetric signal for naked-eye detection. The subject invention further provides exonuclease-based methods for generating structure-switching aptamers from fully folded aptamers and developing electrochemical aptamer-based (E-AB) sensors for rapid and sensitive detection of synthetic cathinones.

The subject invention provides methods, assays and products for detecting small-molecules in a sample, in particular, in both clinical and field settings. The method for detecting a small-molecule target in a sample comprises providing a sample, contacting the sample with an aptamer-based sensor selective for the small-molecule target, and sensitively and rapidly detecting the small-molecule target in the sample. Specifically, the method utilizes EATR-amplified small-molecule sensors based on cooperative binding split aptamers (CBSAs).

Materials and methods for rapid and sensitive detection of small-molecule targets

The subject invention provides materials and methods for detecting the presence of an electron donor. In a specific embodiment, the device detects the presence of dihydronicotinamide adenine dinucleotide (NADH) via a colorimetric change output by the sensing device. In another specific embodiment, the presence of an enzyme capable of catalyzing, or an agent capable of inhibiting, the production of NADH can also be detected by a colorimetric readout using the same device. In some embodiments, dihydronicotinamide adenine dinucleotide phosphate (NADPH) can also be detected using the device provided herein. Advantageously, preferred embodiments of the subject invention provide a low-cost, sensitive device for monitoring the presence of critical biological analytes in a variety of applications.

Materials and methods for rapid visualization of NAD(P)H

The invention pertains to a rapid and specific aptamer-based method for one-step cocaine detection with minimal reagent requirements based on an aptamer sensor that reports the presence of cocaine via the displacement and unquenching of a bound fluorophore molecule. In certain embodiments, the invention provides novel aptamers, which have reduced background fluorescence, bind a fluorophore molecule tightly, and show an increased signal gain in the presence of cocaine.

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Miami, FL, United States of America

Haixiang Yu