%0 Journal Article
%T Tag-free fluorometric aptasensor for detection of chromium(VI) in foods via SYBR Green I signal amplification and aptamer structure transition.
%A Zhu J
%A Yin H
%A Zheng S
%A Yu H
%A Yang L
%A Wang L
%A Geng X
%A Deng Y
%J J Sci Food Agric
%V 0
%N 0
%D 2024 Jun 3
%M 38828647
%F 4.125
%R 10.1002/jsfa.13631
%X <B>BACKGROUND: </B>In response to growing concerns regarding heavy metal contamination in food, particularly chromium (Cr)(VI) contamination, this study presented a simple, sensitive and practical method for Cr(VI) detection.<BR><B>RESULTS: </B>A magnetic separation-based capture-exponential enrichment ligand system evolution (SELEX) method was used to identify and characterize DNA aptamers with a high affinity for Cr(VI). An aptamer, Cr-15, with a dissociation constant (Kd) of 4.42 ± 0.44 μmol L-1 was obtained after only eight rounds of selection. Further innovative methods combining molecular docking, dynamic simulation and thermodynamic analysis revealed that CrO4 2- could bind to the 19th and 20th guanine bases of Cr-15 via hydrogen bonds. Crucially, a label-free fluorometric aptasensor based on SYBR Green I was successfully constructed to detect CrO4 2-, achieving a linear detection range of 60-300 nmol L-1 with a lower limit of detection of 44.31 nmol L-1. Additionally, this aptasensor was able to quantitatively detect CrO4 2- in grapes and broccoli within 40 min, with spike recovery rates ranging from 89.22% to 108.05%. The designed fluorometric aptasensor exhibited high selectivity and could detect CrO4 2- in real samples without sample processing or target pre-enrichment.<BR><B>CONCLUSIONS: </B>The aptasensor demonstrated its potential as a reliable tool for monitoring Cr(VI) contamination in fruit and vegetable products. © 2024 Society of Chemical Industry.