Fluorescent Polymeric Transducer for the Rapid, Simple, and Specific Detection of Nucleic Acids at the Zeptomole Level

Abstract

We report the specific detection of a few hundred molecules of genetic material using a fluorescent polythiophene biosensor. Such recognition is based on simple electrostatic interactions between a cationic polymeric optical transducer and the negatively charged nucleic acid target and can be done in less than 1 h, simply and affordably, and without any chemical reaction. This simple system is versatile enough to detect nucleic acids of various lengths, including a segment from the RNA genome of the Influenza virus.

Conjugated Polyelectrolyte (CPE) Poly{3-[6-(N-methylimidazolium)hexyl]-2,5-thiophene} Complexed with DNA: Relation between Colloidal Level Solution Structure and Chromic Effects

“…Distinctive color changes from red to yellow, 6, 7 yellow to red [38][39][40] or red to violet and to yellow 50 have been observed for CPEs upon charge compensation with various counterions. Similar colorimetric effects are observed for P3ImiHT upon surfactant complexation.…”

“…They are also consistent with Leclerc's idea about DNA being wrapped over P1. [38][39][40] The SAXS curves of the P3ImiHT(DNA) x dilution series normalized to the overall concentration are shown in the Supporting Information and the curves of dilution series are qualitatively similar for each and for P3ImiHT(DNA) 0.5 and P3ImiHT(DNA) 1.3 . The distribution of P3ImiHT and P3ImiHT(DNA) 0.5 are similar, pointing to a 25 Å diameter, while there is a tendency towards thinner 15 Å diameter structures for P3ImiHT(DNA) 1.3 .…”

“…37 It is also possible to prepare imidazolium based block copolymers that provide a platform for microphase separated structures. 30 In a particular example, Leclerc and coworkers [38][39][40] employed the imidazolium substituted CPE, P1)), for probing anionic DNA and proteins. They introduced a sensing method based on the molecular recognition driven backbone planarization.…”

Experimental and Quantum Chemical Calculations of 2-Amino-4,5,6,7-Tetrahydrobenzo[b]Thiophene-3-Carbonitrile

“…They are known for their antidepressant, anticonvulsant, anthelmintic, antispasmodic, antihistaminic, anesthetic, antipruritic, antitussive and analgesic action. Thiophene and its derivatives exhibit diverse biological properties, such as nemoticial, insecticidal, antibacterial, antifungal, antiviral and antioxidant activity [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15].…”

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Vibrational frequencies of 2- 5,6,Thiophene-3-Carbonitrile were calculated using density functional (DFT/B3YLP) method with 6-311++G(d,p) basis set by Gaussian 09. The assignments of the vibrational frequencies have been done by potential energy distribution analysis, using VEDA 4 software.

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