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Biopermissible and Hydrophilic G-CNNPs for Noncooperative Binding with Picomolar of Cancer Drug Etoposide and
Anusree S Gangadharan1, Daniel T Thangadurai1, Valarmani M Vasanthakannan2
1Department of Chemistry and Centre for Nanoscience and Technology, KPR Institute of Engineering and Technology, Coimbatore 641407, Tamilnadu, India.
Abstract:
Etoposide (ETO), a chemotherapeutic agent for lung cancer, requires precise and prompt detection to optimize cancer management and mitigate toxicity. In this study, we present a scalable solid-state methodology for the synthesis of highly hydrophilic (average contact angle 10.73°) graphitic carbon nitride nanoparticles (g-CNNPs) employing urea and trisodium citrate. The synthesized g-CNNPs possess six surface active sites, enabling their function as effective fluorescence sensors for detecting the lung cancer drug ETO at physiological pH. The g-CNNPs demonstrate high selectivity and sensitivity for ETO detection (ΦF 20.29 → 17.95%), with a detection limit (LoD) of 95 pM (R2 = 0.99144), quantification limit (LoQ) of 310 pM, and an association constant (Ka) of 1.0162 M-1. The fluorescence quenching of g-CNNPs by ETO is attributed to intermolecular hydrogen bonding, characterized by static quenching and a noncooperative binding mechanism within the g-CNNPs·ETO complex. Additionally, time-correlated single photon counting (TCSPC) analysis confirms the static quenching of g-CNNPs (lifetime 5.175 → 5.281 ns) upon ETO detection. The formation of the g-CNNPs·ETO complex is verified through DFT studies and a range of physicochemical characterization techniques, including XRD, FE-SEM, HR-TEM, XPS, Raman, FT-IR, and UV-vis. The developed detection method proved effective in identifying ETO in urine samples, achieving high recovery rates between 95.45% and 110.78%. To evaluate their biological efficacy, a series of experiments were conducted, including MTT cytotoxicity assays against mouse fibroblast cell lines L929, the anticancer activity of g-CNNPs toward HT29 cells (with and without light exposure), and ROS generation. Collectively, the results from these real samples and biological studies affirm that biopermissible g-CNNPs are promising candidates for clinical trials.
Insights
We developed a novel fluorescence sensor using graphitic carbon nitride nanoparticles (g-CNNPs) for sensitive and selective detection of the lung cancer drug Etoposide (ETO). This method accurately quanties ETO in urine, showing promise for clinical applications.
Area of Science:
- Nanomaterials Science
- Analytical Chemistry
- Biomedical Engineering
Background:
- Accurate detection of Etoposide (ETO), a crucial lung cancer drug, is vital for optimizing treatment and minimizing toxicity.
- Existing detection methods may lack the sensitivity, selectivity, or practicality required for real-time clinical monitoring.
- Development of novel, efficient sensing platforms is needed for precise ETO quantification.
Purpose of the Study:
- To synthesize highly hydrophilic graphitic carbon nitride nanoparticles (g-CNNPs) for use as a fluorescence sensor.
- To establish a sensitive and selective method for detecting Etoposide (ETO) in biological samples.
- To evaluate the biological safety and potential clinical applicability of the developed g-CNNPs.
Main Methods:
- Scalable solid-state synthesis of hydrophilic g-CNNPs using urea and trisodium citrate.
- Fluorescence spectroscopy to monitor ETO-induced quenching of g-CNNPs.
- Physicochemical characterization (XRD, FE-SEM, HR-TEM, XPS, Raman, FT-IR, UV-vis) and DFT studies.
- Time-correlated single photon counting (TCSPC) for quenching mechanism analysis.
- Validation using spiked urine samples and in vitro biological assays (cytotoxicity, anticancer activity, ROS generation).
Main Results:
- Synthesized hydrophilic g-CNNPs with excellent fluorescence sensing capabilities.
- Achieved highly sensitive (LoD 95 pM) and selective ETO detection via fluorescence quenching.
- Confirmed static quenching mechanism attributed to intermolecular hydrogen bonding.
- Demonstrated high recovery rates (95.45-110.78%) in spiked urine samples.
- g-CNNPs exhibited good biocompatibility and potential anticancer activity.
Conclusions:
- Developed a scalable and effective fluorescence sensing platform for ETO detection using g-CNNPs.
- The method is sensitive, selective, and applicable to real biological samples like urine.
- Biocompatible g-CNNPs show promise as a theranostic agent for lung cancer management, warranting further clinical investigation.
