The increased lead (Pb) content in the environment has an impact on all living beings, including plant growth and quality. The present study aims to investigate the protective roles of zinc (Zn)- and iron (Fe)- nanoparticles (NPs) in alleviating stress symptoms caused by lead (Pb) exposure in Basella alba seedlings. For this purpose, 15 different treatment combinations of seed priming with two NPs at 0 and 200 mg L⁻¹, and five Pb levels (0, 4, 8, 15, 20 mM) were chosen. Pb stress (20 mM) was found to reduce seed germination by 72.8% and seedling growth, particularly root length, by 92% when compared to the control. Under different Pb concentrations, seed priming with ZnNPs (200 mg L⁻¹) and FeNPs (200 mg L⁻¹) increased seed germination by 34.7% and 54.9%, respectively, and root length by 152.9% and 252.9%, respectively. In 20 mM Pb stress, NPs primed seedling showed decrease in Pb content by 33.7% with ZnNPs and 32.6% with FeNPs. Increased Pb stress resulted in increased reactive oxygen species (ROS) generation (H₂O₂) and lipid peroxidation (MDA) compared to non-Pb stressed seedlings. However, increased antioxidants in the NPs treatments such as SOD, CAT, POD and proline content, scavenged these ROS. Considering all the parameters under study, priming alleviated Pb stress in the following order: FeNPs > ZnNPs > hydropriming > control. To summarise, seed priming with Zn- and Fe-NPs has the potential to alleviate Pb toxicity via reduced Pb uptake, ROS generation and lipid peroxidation as well as increased proline content and activation of antioxidant enzymatic system.

A novel structurally simple calix[4]arene appended 8-amidoquinoline linked conjugate was synthesized and has been used as a turn-on fluorescence probe for Zn²⁺ and turn off fluorescence probe for F⁻. Moreover, this probe has been applied for Zn²⁺ detection in blood serum upto 8.7 μM and fluoride detection upto 22 nM in waste water samples, using emission spectra.

We developed a new, advanced, simple and non enzymatic approach for the colorimetric detection of glucose based on calix[4]arene/phenyl boronic acid (CX-PBA)functionalized gold nanoparticles (AuNPs). This molecular receptor proficiently and selectively recognizes glucose due to its ability to reversibly bind diol-containing compounds. The assembly was characterized by transmission electron micrograph (TEM), dynamic light scattering (DLS), UV-Vis, FT-IR, ESI-MS and ¹H NMR spectrometry, which demonstrates the binding affinity for glucose via a boronic acid–diol interaction. The linear range for glucose was found to be 5–100 nM with phosphate buffer pH 10, with a lower detection limit of 4.3 nM. Interference by other saccharides was negligible. The biosensor has been successfully applied to estimate the glucose in human blood serum samples and the results compared well to an automatic analyzer. With the advantages of high sensitivity, selectivity and low sample volume, this method is potentially suitable for the on-site monitoring of glucose.

Here, for the first time, we designed an ultrasensitive nanocurcumin based nanomaterials surface energy transfer (NSET) probe for detection of trace amount of TNT with excellent sensitivity (1 nM) and selectivity over other nitro explosives via nanoaggregation and we found the largest fluorescent enhancement to date for sensing TNT (upto 800 fold).

A novel PET with ICT based substituted calix[4]arene fluroionophore was synthesized and used for detection of Cu²⁺ and F⁻ by emission spectra. The detection limit of the synthesized receptor was found to be 4.16 nM for Cu²⁺ and 2.15 nM for F⁻. Moreover, this probe has been applied for recognition of Cu²⁺ in blood serum and F⁻ from waste water.

We demonstrate a facile strategy for preparing highly stable silver nanoprobe modified p-sulphonato-calix[4]resorcinarene in aqueous media. We also report the efficient and selective sensing properties of the novel assembly for organophosphorus insecticides and its great potential for application to real-time in situ detection of organophosphorus pesticides in waste water.