Ultrasensitive and specific photoelectrochemical sensor for hydrogen peroxide detection based on pillar[5]arene-functionalized Au nanoparticles and MWNTs hybrid BiOBr heterojunction.

A photoelectrochemical sensor for target detection of hydrogen peroxide was designed based on a new heterojunction nanocomposite which was sulfhydryl-borate ester-modified A1/B1-type pillar[5]arene (BP5)-functionalized Au NPs and multi-walled carbon nanotubes hybridized with bismuth bromide oxide (Au@BP5/MWNTs-BiOBr). The specific sensor was based on the direct induction of oxidation by hydrogen peroxide of the borate ester group of pillar[5]arene. Additionally, the local surface plasmon resonance (LSPR) of Au NPs enhanced visible light capture, the host-guest complexation of BP5 with H2O2 enhanced photocurrent response, the layer-by-layer stacked nanoflower structure of BiOBr provided large specific surface area with more active sites, and the conductivity of MWNTs enhanced the charge separation efficiency and significantly improves the stability of PEC. Their synthesis effect significantly increased the photocurrent signal and further enhanced the detection result. Under the optimal conditions, the linear concentration range of H2O2 detected by the Au@BP5/MWNTs-BiOBr sensor was from 1 to 60 pmol/L. The limit of detection (LOD) and the limit of quantification (LOQ) of the method were 0.333 pmol/L and 1 pmol/L, respectively, and the sensitivity was 6.471 pmol/L. Importantly, the PEC sensor has good stability, reproducibility, and interference resistance and can be used for the detection of hydrogen peroxide in real cells.

Pillar[5]arene-based [1]rotaxanes with salicylaldimine as the stopper: synthesis, characterization and application in the fluorescence turn-on sensing of Zn2+ in water.

Two pillar[5]arene-based [1]rotaxanes with salicylaldimine as the stopper were synthesized and characterized fully, and could be further applied in the fluorescence turn-on sensing of Zn2+ in water.

An specific photoelectrochemical sensor based on pillar[5]arenes functionalized gold nanoparticles and bismuth oxybromide nanoflowers for bovine hemoglobin recognition.

In this work, the ultrasensitive photoelectrochemical (PEC) sensor for the detection of bovine hemoglobin (BHb) was developed based on water-soluble pillar[5]arenes (WP5) functionalized gold nanoparticles (Au NPs) and bismuth oxybromide (BiOBr) nanoflowers (Au@WP5/BiOBr). The photoelectrical signal of dopamine (DA) was decreased after adding the different concentrations of BHb due to the formation of hydrogen bond between the COOH groups of BHb molecules and the NH2 group of DA, which could achieve the indirect detection of BHb. Benefiting from the photo-generated electron-holes of BiOBr nanoflowers, the localized surface plasmon resonance (LSPR) effect of Au NPs, the host-guest interaction of WP5 between and DA, the PEC sensor showed a specificallyrecognize toward BHb with a wide detection range of 1.0 × 10-11-1.0 × 10-1 mg/mL and a detection limit of 4.2 × 10-12 mg/mL (S/N = 3). Additionally, the proposed PEC sensor also displayed good stability, remarkable selectivity and provided a promising strategy of design pillar[5]arenes functionalized photoelectric activity nanomaterials for PEC sensing application.

Ultrasensitive photoelectrochemical immunosensor for carcinoembryonic antigen detection based on pillar[5]arene-functionalized Au nanoparticles and hollow PANI hybrid BiOBr heterojunction.

In this study, an ultrasensitive and specific photoelectrochemical (PEC) immunosensor was designed for carcinoembryonic antigen (CEA) detection. Benefitting from the ascorbic acid (AA) used as an electron donor that led to a notable change in the photocurrent density, pillar[5]arene functionalized Au and Polyaniline-Bismuth oxybromide heterojunction (Au@WP5/PANI-BiOBr) displayed superior PEC performance for CEA sensing. In detail, the localized surface plasmon resonance (LSPR) of the Au NPs and host-guest complexation between WP5 and AA increased the photocurrent signal, the photogenerated holes on BiOBr accelerated the oxidation of AA, and the fast electron transfer of the hollow PANI tubes benefited an increase in the photocurrent. The antibody effectively bound with CEA when bovine serum albumin blocked the residual sites on the Au@WP5/PANI-BiOBr electrode, generating a clear decrease in photocurrent density in AA solution. Under the optimum condition, the developed PEC immunosensor exhibited a sensitive response to CEA which was linear in the range of 0.01 ng mL-1 to 50 ng mL-1 with a detection limit of 3 pg mL-1. The proposed PEC immunosensor displayed high specificity, good stability, and excellent reproducibility, paving a new way to construct sensitive and specific photoactive heterojunction materials for biomarker immunosensing.

An enhanced photo-electrochemical sensor constructed from pillar [5]arene functionalized Au NPs for ultrasensitive detection of caffeic acid.

Pillar [5]arene, a new water-soluble carboxylatopillar [5]arene ammonium salts (WP5), has been employed as the host for complexation of guest molecules. Herein, a visible light driven WP5 functionalized gold nanoparticles (Au@WP5) was fabricated for ultrasensitive photelectrochemical (PEC) detection of caffeic acid (CA). The ultraviolet-visible spectrum characteristics, PEC response results of samples in caffeic acid solution confirm the localized surface plasmon resonance effect of Au NPs and the host-guest interaction between WP5 and CA are responsible for the enhanced PEC sensing performance. Under optimal conditions, the sensitive PEC sensor constructed with Au@WP5 exhibited the concentration linear range from 0.025 µM to 370 µM and a detection limit of 0.01 µM (S/N = 3). Importantly, the good anti-interference ability, stability and reproducibility of the proposed PEC sensor providing the promising detection application of pillar [5]arene functionalized photoactive materials in food and drinks.

GOx-assisted synthesis of pillar[5]arene based supramolecular polymeric nanoparticles for targeted/synergistic chemo-chemodynamic cancer therapy.

BACKGROUND: Cancer is the most serious world's health problems on the global level and various strategies have been developed for cancer therapy. Pillar[5]arene-based supramolecular therapeutic nano-platform (SP/GOx NPs) was constructed successfully via orthogonal dynamic covalent bonds and intermolecular H-bonds with the assistance of glucose oxidase (GOx) and exhibited efficient targeted/synergistic chemo-chemodynamic cancer therapy. METHODS: The morphology of SP/GOx NPs was characterized by DLS, TEM, SEM and EDS mapping. The cancer therapy efficinecy was investigated both in vivo and in vitro. RESULTS: SP/GOx NPs can load drug molecules (Dox) and modify target molecule (FA-Py) on its surface conveniently. When the resultant FA-Py/SP/GOx/Dox NPs enters blood circulation, FA-Py will target it to cancer cells efficiently, where GOx can catalyst the overexpressed glucose to generate H2O2. Subsequently, the generated H2O2 in cancer cells catalyzed by ferrocene unit to form •OH, which can kill cancer cells. Furthermore, the loaded Dox molecules released under acid microenvironment, which can further achieve chemo-therapy. CONCLUSION: All the experiments showed that the excellent antitumor performance of FA-Py/SP/GOx/Dox NPs, which provided an new method for pillar[5]arene-based supramolecular polymer for biomedical applications.

Rim-differentiated pillar[5]arene based nonporous adaptive crystals.

The first rim-differentiated pillar[5]arene based nonporous adaptive crystals (NACs) were developed and used to separate dichloromethane from a halomethane mixture with 99.1% purity.