Ultrasensitive detection of lead (II) based on fluorescent aptamer-functionalized carbon nanotubes.
Lead contamination is a serious environmental problem with toxic effects in human. Here, we developed a simple and sensitive sensing method employing ATTO 647N/aptamer-SWNT ensemble for detection of Pb(2+). This method is based on the super quenching capability of single-walled carbon nanotubes (SWNTs), high affinity of the aptamer toward Pb(2+) and different propensities of ATTO 647N-aptamer and ATTO 647N-aptamer/Pb(2+) complex for adsorption on SWNTs. In the absence of Pb(2+), the fluorescence of ATTO 647N-aptamer is efficiently quenched by SWNTs. Upon addition of Pb(2+), the aptamer binds to its target, leading to the formation of a G-quadruplex/Pb(2+) complex and does not interact with SWNTs and ATTO 647N-aptamer starts fluorescing. This sensor exhibited a high selectivity toward Pb(2+) and a limit of detection (LOD) as low as 0.42 nM was obtained. Also this sensor could be applied for detection of Pb(2+) ions in tap water and biological sample like serum with high sensitivity.
Department of Pharmaceutical Biotechnology, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
Seyed Mohammad
SM
Taghdisi
School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran.
Somayeh Sarreshtehdar
SS
Emrani
Department of Toxicology, School of Pharmacy, Zabol University of Medical Sciences, Zabol, Iran.
Kaveh
K
Tabrizian
Nanotechnology Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran.
Mohammad
M
Ramezani
Pharmaceutical Research Center, School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address: abnouskh@mums.ac.ir.
Khalil
K
Abnous
Cardiovascular Research Center, Ghaem Hospital, Mashhad University of Medical Sciences, Mashhad, Iran. Electronic address: ahmad_sarreshtedar@yahoo.com.
Ahmad Sarreshtehdar
AS
Emrani
D000818:Animals; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D060766:Drinking Water / Q000032:analysis; D004785:Environmental Pollutants / Q000032:analysis* / Q000097:blood; D005456:Fluorescent Dyes / Q000737:chemistry*; D007854:Lead / Q000032:analysis* / Q000097:blood; D057230:Limit of Detection; D037742:Nanotubes, Carbon / Q000737:chemistry*; D051381:Rats
D052157:Aptamers, Nucleotide; D060766:Drinking Water; D004785:Environmental Pollutants; D005456:Fluorescent Dyes; D037742:Nanotubes, Carbon; D007854:Lead
ATTO 647N; Aptamer; Lead; SWNT; Sensor