A New Sensitive Method for Quantitative Determination of Cisplatin in Biological Samples by Kinetic Spectrophotometry

Utilizing a graphene quantum dot/hydrogel nanocomposite for determination of cisplatin in urine samples

Currently, the growth and development of cancer are rising in the world, and as a result, the use of anticancer drugs such as cisplatin has also increased. Considering that the therapeutic index of anticancer drugs is low, it is essential to design and develop an accurate and correct method to analyze and determine the concentration of anticancer drugs in the biological samples. In this study, graphene quantum dots/hydrogel nanocomposite was used to determine cisplatin concentration in urine samples. A three-dimensional network of polyvinyl alcohol hydrogel was composited with graphene quantum dots and used as a probe for the determination of cisplatin. The morphology and characterization of the probe were studied using high-resolution transmission electron microscopy, dynamic light scattering, energy-dispersive X-ray spectroscopy, and Fourier transform infrared spectroscopy. This platform showed a linear calibration curve in the range from 4.3 to 25.0 ng mL-1 with a detection limit of 1.2 ng mL-1. The relative intra- and inter-day standard deviations of the probe for the determination of cisplatin were 1.8% and 3.6% (n = 5), respectively. The validated method was used for determination of cisplatin in urine samples of patients receiving this medication with acceptable results and good recoveries.

Selective fluorescence turn-on detection of combination cisplatin-etoposide chemotherapy based on N-CDs/GSH-CuNCs nanoprobe

Cisplatin (CIS) and etoposide (ETP) combination therapy is highly effective for treating various cancers. However, the potential for pharmacokinetic interactions between these drugs necessitates selective sensing methods to quantitate both CIS and ETP levels in patient's plasma. This work develops a dual fluorescence probe strategy using glutathione-capped copper nanoclusters (GSH-CuNCs) and nitrogen-doped carbon dots (N-CDs) for the simultaneous analysis of CIS and ETP. The fluorescence signal of GSH-CuNCs at 615 nm increased linearly with CIS concentration while the N-CD emission at 480 nm remained unaffected. Conversely, the N-CD fluorescence was selectively enhanced by ETP with no interference with the CuNC fluorescence. Extensive materials characterization including UV-vis, fluorescence spectroscopy, XRD, and TEM confirmed the synthesis of the nanoprobes. The sensor showed high sensitivity with limits of detection of 6.95 ng mL-1 for CIS and 7.63 ng mL-1 for ETP along with excellent selectivity against potential interferences in rabbit plasma. Method feasibility was demonstrated with application to real rabbit plasma samples. The method was further applied to estimate the pharmacokinetic parameters of CIS before and after ETP coadministration. The dual nanoprobe sensing strategy enables rapid and selective quantitation of CIS and ETP levels to facilitate therapeutic drug monitoring and optimization of combination chemotherapy regimens.