| dc.description.abstract | In the present study, the phthalocyanine (Pc) integrated mercaptopropionic acid capped quantum dot
(mpa@QD) biosensor has been developed for the quantitative determination of G-quadruplex and doublestranded
DNA. The working principle of the developed biosensor platform is based on the quenching of the
emission signal of the mpa@QD in the presence of Pc (closed position) and the recovery of the fluorescence
signal in the presence of DNA (open position). The parameters affecting biosensor performance, such as Pc type
and concentration, were optimized. Since the developed biosensor aimed to determine G-quadruplex and doublestranded
DNA in biological samples, the effect of common ions (such as Na+, Mg2+) and serum albumin found in
many biological matrices on the biosensor performance were examined. The effect of common ions on biosensor
signal was negligible, except Zn2+. The analytical properties of the biosensor, such as linear range, calibration
sensitivity, relative standard deviation %, the limit of detection, and quantification, were determined. The limit
of detection and quantification values were found 0.055 μM and 0.18 μM for AS1411, 0.061 μM and 0.20 μM for
Tel21, 0.038 μM and 0.13 μM for Tel45 and 0.091 μM and 0.30 μM for ctDNA. Several different synthetic
samples were prepared. The spiked synthetic samples such as mammalian cell medium were used to evaluate the
analytical performance of Pc-mpa@QD. All synthetic samples were prepared with polyethylene glycol, which
resembles biological samples’ crowded environment. | tr |
