Resonance light scattering aptasensor for urinary 8-hydroxy-2′-deoxyguanosine based on magnetic nanoparticles: a preliminary study of oxidative stress association with air pollution

Abstract

An aptamer based method is described for the determination of 8-hydroxy-2'-deoxyguanosine (8-OHdG) using resonance light scattering (RLS). Magnetic nanoparticles (MNPs) were employed as RLS probes. The probe DNA was placed on the surface of MNPs, which produces a rather low RLS signal. If, however, probe DNA hybridizes with the aptamer against 8-OHdG, a sandwich structure will be formed. This results in a significant enhancement of RLS intensity. The aptamer was used as the recognition element to capture 8-OHdG. 8-OHdG has a stronger affinity for the aptamer than probe DNA, and the conformation of the aptamer therefore switches from a double-stranded to a G-quadruplex structure. As a result, MNPs labeled with probe DNA are released, and RLS intensity decreases. The method allows 8-OHdG to be detected with a linear response in the 32 pM - 12.0 nM concentration range and an 11 pM limit of detection (at 3.29S/m, according to the recent recommendation of IUPAC). The MNPs can be reused 5 times by applying an external magnetic field for collection. The method was successfully applied to analyze human urine samples for its content of 8-OHdG. It was also found that the levels of 8-OHdG noticeably increased with the increase of the Air Quality Index. Conceivably, the method is a viable tool to investigate the relationship between 8-OHdG levels and the effect of air pollution. Graphical abstract A reusable sensing strategy was constructed to detect urinary 8-OHdG based on "turn-off" resonance light scattering. The LOD was as low as 11 pM. This study showed some preliminary data for the association between oxidative stress and air pollution.

Development of Low-Cost AuNP-Based Aptasensors with Truncated Aptamer for Highly Sensitive Detection of 8-Oxo-dG in Urine

“…The limits of detection obtained from our portable device were as low as 12.9 nM (38-nt aptasensor) and 9.8 nM (66-nt aptasensor), demonstrating its ability to detect 8-oxo-dG in real human urine as both LODs are much lower than the threshold value (280 nM) for normal human urine. 41 Our 38-nt aptasensor was compared with previously reported methods using the 66-nt aptamer, as shown in Table 3 . Our method surpassed Rayleigh light scattering (RLS) 39 and chiroplasmic 42 techniques in a wide linear range.…”

Analytical and Structural Studies for the Investigation of Oxidative Stress in Guanine Oligonucleotides

“…Beyond the information on the quantity, concentration or frequency of oxidative lesions, in some cases, additional pieces of information can hint at temperature-dependence, kinetic and thermodynamic parameters [29], processes preceding oxidation [41] or eventual cross-link formation in short ON tracts [44]. The transformation of G can take place in different sequence contexts, including GQs, which have also been utilized in some analytical methods [34,35,[38][39][40].…”

“…Magnetic nanoparticles (MNPs) were employed as resonance light scattering (RLS) probes [40]. The probe DNA was placed on the surface of MNPs, which produces a rather low RLS signal.…”

“… Magnetic nanoparticles in the resonance light scattering (RLS) probe for the detection of o 8 dGuo [ 40 ]. …”

Aptamer-Based Biosensors for Environmental Monitoring

“…One area of aptamer-based environmental monitoring that could use more researchers' attention is air quality. With the exception of some work that focused on developing optical [fluorescent (Ammanath et al, 2018;, colorimetric (Ammanath et al, 2018;Choodet et al, 2019;Toomjeen et al, 2019), and resonance light scattering (Tao et al, 2018)] and electrochemical (Zheng et al, 2019) biosensors for 8-hydroxy-2 ′ -deoxyguanosine (8-OHdG), a biomarker for oxidative stress that can be detected in urine and has been associated with air pollution (Tao et al, 2018), only one recent study has focused on using aptamers to monitor air quality. Radon is a colorless, odorless, toxic gas which has been designated by the World Health Organization and the International Cancer Organization as a first-class environmental carcinogen (Li S. et al, 2018).…”