Array of potentiometric sensors for simultaneous determination of copper, silver, and cadmium ions in complex mixtures

Fluorescent Turn-On Anthracene-Based Aluminum(III) Sensor for a Therapeutic Study in Alzheimer's Disease Model of Drosophila

A new anthracene-based probe (E)-N'-(1-(anthracen-9-yl)ethylidene)-2-hydroxybenzohydrazide (AHB) has been efficiently synthesized and characterized by various spectroscopic methods. It exhibits extremely selective and sensitive fluorometric sensing of Al3+ ions with a large enhancement in the fluorescent intensity due to the restricted photoinduced electron transfer (PET) mechanism with a chelation-enhanced fluorescence (CHEF) effect. The AHB-Al3+ complex shows a remarkably low limit of detection at 0.498 nM. The binding mechanism has been proposed based on Job's plot, 1H NMR titration, Fourier transform infrared (FT-IR), high-resolution mass spectrometry (HRMS), and density functional theory (DFT) studies. The chemosensor is reusable and reversible in the presence of ctDNA. The practical usability of the fluorosensor has been established by a test strip kit. Further, the therapeutic potential of AHB against Al3+ ion-induced tau protein toxicity has been tested in the eye of Alzheimer's disease (AD) model of Drosophila via metal chelation therapy. AHB shows great therapeutic potential with 53.3% rescue in the eye phenotype. The in vivo interaction study of AHB with Al3+ in the gut tissue of Drosophila confirms its sensing efficiency in the biological environment. A detailed comparison table included evaluates the effectiveness of AHB.

Anthracene scaffold as highly selective chemosensor for Al3+ and its AIEE activity

Fluorescent chemosensor, 3-(Anthracen-2-yliminomethyl)-benzene-1,2-diol (ANB) has been synthesized by one-step condensation of 2-aminoanthracene and 2,3-dihydroxybenzaldehyde and characterized using ¹H-NMR, FT-IR and Mass spectroscopic techniques. The probe ANB was found to be an efficient 'turn-on' fluorescence chemosensor for the selective detection of Al³⁺ ion over other metal ions in an aqueous solution. The chemosensor exhibits ~ 27-fold enhancement of emission intensity in presence of Al³⁺ ion. Fluorescence quantum values for ANB and (Al³⁺-ANB)-complex are 0.004 and 0.097, respectively. In addition, the binding constant and the limit of detection were found to be 1.22 × 10⁴ M^-1 and 0.391 µM, respectively. The chemosensor ANB binds to Al³⁺ ions in 2:1 stoichiometric ratio which was supported by Job's plot, ¹H-NMR titration and florescence titration. Fluorescence reversibility of the sensor complex was well established by adding EDTA in the same condition and a molecular INHIBIT logic gate was fabricated using this reversible nature of the sensor complex. Additionally, the chemosensor ANB shows a novel aggregation-induced enhanced emission phenomenon, where the aggregate hydrosol of ANB shows enhance emission intensity.

Prepared carbon dots from wheat straw for detection of Cu2+ in cells and zebrafish and room temperature phosphorescent anti-counterfeiting

The green synthesis of fluorescent carbon dots from biomass is critical for their sustainable application. Herein, using wheat straw as a single precursor, carbon dots (CDs) were prepared through a one-step carbonization process, and the obtained CDs have intense blue luminescence and excitation-independent photoluminescent behavior. The solution of CDs shows good biocompatibility, and low cytotoxicity successfully used as hopeful bioimaging and biosensing probe for Cu²⁺ in HepG2 cells and zebrafish. Based on CDs, boron-doped carbon dots with IPA shells (CDs@IPA) can be obtained by doping boron element and isophthalic acid (IPA) coating. CDs@IPA irradiated with different wavelength ultraviolet lamps shows different solid fluorescence, while turning off the ultraviolet lamp can produce green visible room temperature phosphorescence (RTP) to the naked eyes for 5 s. The two kinds of wheat straw-based carbon dots have bifunctional luminescence properties and can be used to detect Cu²⁺ and serve as RTP anti-counterfeiting signs to ensure information security.

The first highly selective turn “ON” fluorescent sensor for vanadyl (VO2+) ions: DFT studies and molecular logic gate behavior

We report the first antipyrine-derived fluorescent chemosensor for highly selective and sensitive detection of vanadyl ions by an inhibited PET mechanism, with DFT studies.