The present study was motivated by the need to design a safe nano-carrier for the delivery of doxorubicin which could be tolerant to normal cells. PCL₆₃-b-PNVP₉₀ was loaded with doxorubicin (6 mg/ml), and with 49.8% drug loading efficiency; it offers a unique platform providing selective immune responses against lymphoma. In this study, we have used micelles of amphiphilic PCL₆₃-b-PNVP₉₀ block copolymer as nano-carrier for controlled release of doxorubicin (DOX). DOX is physically entrapped and stabilized in the hydrophobic cores of the micelles and biological roles of these micelles were evaluated in lymphoma. DOX loaded PCL₆₃-b-PNVP₉₀ block copolymer micelles (DOX-PCL₆₃-b-PNVP₉₀) shows enhanced growth inhibition and cytotoxicity against human (K-562, JE6.1 and Raji) and mice lymphoma cells (Dalton's lymphoma, DL). DOX-PCL₆₃-b-PNVP₉₀ demonstrates higher levels of tumoricidal effect against DOX-resistant tumor cells compared to free DOX. DOX-PCL₆₃-b-PNVP₉₀ demonstrated effective drug loading and a pH-responsive drug release character besides exhibiting sustained drug release performance in in-vitro and intracellular drug release experiments. Unlike free DOX, DOX-PCL₆₃-b-PNVP₉₀ does not show cytotoxicity against normal cells. DOX-PCL₆₃-b-PNVP₉₀ prolonged the survival of tumor (DL) bearing mice by enhancing the apoptosis of the tumor cells in targeted organs like liver and spleen.

Very recently, we have reported a novel peroxidase mimetic material, brominated graphene (GBR) having ∼3% bromine content, which, in combination with H₂O₂ and 3,3′,5,5′-tetramethylbenzidine (TMB), has shown the property of S²⁻ ion recognition (Anal. Chem., 2017, 89, 783–791). In the present work, we further have investigated the kinetic assay and colorimetric sensing ability of GBR towards hydrogen peroxide (H₂O₂) and glucose. The Michaelis–Menten constants (K_m) and maximum initial velocities (V_max) of GBR have been found to be 10.98 mM and 3.60 × 10⁻⁸ M s⁻¹, respectively, for H₂O₂ and 0.83 mM and 0.68 × 10⁻⁸ M s⁻¹, respectively, for TMB. A sensor combining TMB and GBR has been fabricated, which, upon addition to H₂O₂ or glucose with glucose oxidase solution at pH 4.48, showed colorimetrically a significant increase in the oxidation of TMB. The fabricated sensor system has displayed linearity for H₂O₂ and glucose estimation in the range 0.50–5.00 mM and 40–100 mM, respectively, and the corresponding limits of detection are found to be 0.417 and 28.41 mM, respectively. The present sensor system is also highly reproducible and selective. The results of real samples using this colorimetric method have been found to be comparable with the conventional auto-analyser method.