Chemosensor Materials Research Articles

Spectrophotometric analysis and mechanistic insights investigation of a developed CT complex as colorimetric real-time sensing performance towards Fe2+ in aqueous medium

A newly developed charge transfer complex (CTC) is explored for colorimetric real-time sensing behavior towards the Fe2+ ion, as a highly selective real-time colorimetric chemosensor material. The synthesized and characterized CTC / P1, [(2HP)+(SA)−] is cheap, remarkably distinctive, and simple to manufacture. Beyond the exposure limitations, iron is also the most common cofactor in enzyme reactions, which is, therefore a crucial part of life. However, too much or not enough iron leads to anemia, liver damage, cancer, Alzheimer's disease, and Parkinson's disease. In this report, unusual sensing capacity has been reported with a relatively low detection limit of 1.247 ppb for Fe2+ ions in aqueous medium, which was lowest at 1.267 ppb in previous reports of CTC sensors. By using a static quenching process, the incredible sensing behavior of this material as a chemosensor was determined. Colorimetric sensing behavior in real-time has also been observed. The complex has been described using a variety of methods, including UV-visible and FTIR spectroscopy. In FTIR spectra, the CTC (P1) showed a change in wavenumber when compared to its reactants. Furthermore, the complex's stoichiometry was measured using UV-visible spectroscopy by taking mixture with an equimolar ratio using the straight-line approach known as the Benesi-Hildebrand equation, which was found to be 1:1. Oscillator strength (f), transition dipole moment (μEN), molar extinction coefficient (εCT), energy of interaction (ECT), and stability constant (KCT) were among the thermodynamic and physical characteristics studied. Van't Hoff's equation was used to compute other parameters such as Gibbs free energy (G°), absorptivity coefficient (ε), Resonance energy (RN), etc. [O+—H……O−] hydrogen bonding was used to depict the interaction between reactants (salicylic acid and 2-hydroxypyridine). The stability of the P1 as a function of temperature is demonstrated through TG/DTA analysis.

Chemosensor material as a metal–organic framework with potassium-based perylene tetracarboxylic acid for copper and lead detection

Heavy metal ions stand out as highly toxic pollutants, playing a pivotal role in various human diseases. Consequently, the development of advanced detection methods becomes imperative for global public health. A proven and effective strategy for metal ion detection involves the use of fluorescent chemosensors. In this context, we synthesized metal–organic frameworks (MOFs) based on perylene to create potassium-based MOFs functioning as an efficient detection probe for metal ion detection. Proton nuclear magnetic resonance (NMR) spectral analysis revealed only two distinct types of hydrogen signals are observed from K4PTC, and no hydrogen signals originating from any residual K4PTC are detected. Similarly, In the 13C NMR spectra, the most downfield signal observed at 176.9 ppm is conveniently assigned to the carbonyl carbon of the K4PTC. The probe displayed diminished absorbance and fluorescence intensity upon the introduction of Cu2+ and Pb2+, suggesting K4PTC’s potential as a sensor for detecting these metal ions. The above findings indicate that loading metal ions into the K4PTC system weakens the oxygen-potassium interaction, signifying the interaction between the metal ions and our probe. Interestingly, the limit of detection (LOD) for our sensor material is highly effective for detecting these metal ions. Consequently, this research serves as a significant reference for the sensitive monitoring of metal pollutants in the environment.

Multifunctional fluorogenic probes from hydrazide schiff base-modified polyvinylpyrrolidone to detect Al3+ in aqueous environment and living cells

Recent efforts have been made to develop chemosensors for aluminum cation (Al3+) detection to monitor the concentration of an aluminum metal ion in both the environment and biological systems due to the high health risks associated with aluminum exposure. Hence the development of chemosensory with multifunctionality has advantages over traditional approaches. Therefore, multi-functional chemosensor materials were fabricated with colorimetric, chromogenic, and fluorogenic probes from the hydrazone-based polyvinylpyrrolidone (PVP-NDHIP) were designed by Atom Transfer Radical Addition Polymerization (ATRP) approach. The Schiff base moiety was conjugated with different chain lengths of PVP to provide good aqueous solubility, low detection limits, enhanced selectivity, and sensitivity of the probes. As a result, the PVP-NDHIP probes showed substantial fluorescence enhancement in linearity upon adding Al3+ ions with a low detection limit of a few nanomolar by fluorescence detection in an aqueous solution. Especially, PVP-NDHIP with Mw of 10,000 g/mol (PVP-NDHIP10k) presented the most sensitive absorption and fluorescence titrations performance with 26.4 nM and 3.9 nM, respectively. Furthermore, the PVP-NDHIP probes demonstrated excellent performance in water and various aqueous cosolvent environments, such as DIW/DMSO, DIW/THF, DIW/DMF, DIW/Ethanol, and DIW/Methanol. Moreover, the obtained probe was used for internalization and Al3+ intracellular imaging. The findings explained that hydrazone-based polyvinylpyrrolidone could create a critical role as a multifunctional approach in both environmental contamination and Al3+ related pathway in a biological system.

BODIPY Immobilized MCM‐41 Based Multianalyte Sensor: Application in Detection and Removal of Trivalent (Al3+, Cr3+) and Divalent (Cu2+, Hg2+) Metal Ions in Aqueous Media

AbstractIn the present study, a novel p‐phenylcarboxylic acid BODIPY (L) immobilized MCM‐41 based solid chemosensor material L‐propylsilyl@MCM‐41 (MS4) was developed to detect multiple metal ions in a pure aqueous medium. The synthesized solid chemosensor material MS4 shows high sensitivity and removal ability towards trivalent (Al3+, Cr3+) and divalent (Cu2+, Hg2+) metal ions. The emission intensity of MS4 enhanced multifold selectively in the presence of trivalent (Al3+, Cr3+) metal ions and shows quenching in the presence of divalent (Cu2+, Hg2+) metal ions. The limit of detection was calculated to be in the nanomolar range with Al3+, Cr3+, Cu2+, and Hg2+ metal ions in the aqueous medium. The spectroscopic and analytical results suggest that MS4 selectively binds with Al3+ and Cr3+ through −NH functionality and with Hg2+ and Cu2+ through −COOH functionality of p‐phenylcarboxylic acid BODIPY (L). Further, MS4 selectively removes Al3+, Cr3+, Cu2+, and Hg2+ metal ions from the aqueous media with removal efficiency of 97.28 %, 96.34 %, 87.19 %, and 95.63 %, respectively. No noticeable change in the concentration was observed for other metal ions. The recycling potential of MS4 was evaluated using EDTA for up to seven cycles with no significant reduction in sensing capability.

Atmospheric Pressure Solvothermal Synthesis of Nanoscale SnO2 and Its Application in Microextrusion Printing of a Thick-Film Chemosensor Material for Effective Ethanol Detection.

The atmospheric pressure solvothermal (APS) synthesis of nanocrystalline SnO2 (average size of coherent scattering regions (CSR)-7.5 ± 0.6 nm) using tin acetylacetonate as a precursor was studied. The resulting nanopowder was used as a functional ink component in microextrusion printing of a tin dioxide thick film on the surface of a Pt/Al2O3/Pt chip. Synchronous thermal analysis shows that the resulting semiproduct is transformed completely into tin dioxide nanopowder at 400 °C within 1 h. The SnO2 powder and the resulting film were shown to have a cassiterite-type structure according to X-ray diffraction analysis, and IR spectroscopy was used to establish the set of functional groups in the material composition. The microstructural features of the tin dioxide powder were analyzed using scanning (SEM) and transmission (TEM) electron microscopy: the average size of the oxide powder particles was 8.2 ± 0.7 nm. Various atomic force microscopy (AFM) techniques were employed to investigate the topography of the oxide film and to build maps of surface capacitance and potential distribution. The temperature dependence of the electrical conductivity of the printed SnO2 film was studied using impedance spectroscopy. The chemosensory properties of the formed material when detecting H2, CO, NH3, C6H6, C3H6O and C2H5OH, including at varying humidity, were also examined. It was demonstrated that the obtained SnO2 film has an increased sensitivity (the sensory response value was 1.4-63.5) and selectivity for detection of 4-100 ppm C2H5OH at an operating temperature of 200 °C.

Vapourchromic alkali metal ions complexes based on 2-phenmethylamino-7-methyl-1,8-naphthyridine

A series of 2-phenmethylamino-7-methyl-1,8-naphthyridine/alkali metal ion (Li + and Na + ) complexes have been synthesized using a polymeric medium (poly(acrylic acid)) as the key activating component. Upon exposure to methanol or ethanol vapour at ambient temperature, the emission colour of prepared complexes in solid powder and thin film states changes from red-orange or pink to blue, respectively. These phenomena are reversible and rapid (about 5-10 s), hence, the prepared complexes have potential applications as chemosensor materials for detection of volatile methanol vapour.

Self-Reporting Molecularly Imprinted Polymer with Covalently Immobilized Ferrocene Redox Probe for Selective Electrochemical Sensing of P-Synephrine

Molecularly imprinted polymers (MIPs) belong to the illustrious examples of bio-mimicking recognizing materials.1 They have found numerous applications in the fabrication of selective chemosensors.2 Their analytical parameters, such as sensitivity, selectivity, and detectability, are almost as high as those of biosensors. Additionally, MIP based chemosensors are superior to biosensors concerning their ease of fabrication, durability, and tolerance to harsh conditions, including elevated or decreased temperature, high ionic strength, extreme pH values, the presence of heavy metal ions and organic solvents in the samples. Conductive MIPs have recently become more frequently applied. That is mainly due to the easy control of MIPs deposition as thin films by electropolymerization.3 For the electrochemical determination of non-electroactive analytes, some external redox probe is usually added to the test solution. It is assumed that target analyte molecules' binding into molecular cavities causes MIP film swelling or shrinking. According to the so-called "gate effect" mechanism, this polymer "breathing" causes changes in the redox probe permeability through an MIP film, thus changing faradaic current corresponding to the redox probe's reduction or oxidation in cyclic voltammetry (CV) and differential pulse voltammetry (DPV) determinations.4-5 This mechanism is operative for nonconductive MIP films. Another mechanism may be considered for surface imprinted macromolecular compounds, e.g., proteins. A drop in the faradaic current of the redox probe accompanying protein adsorption originates from physical blocking of the electrode surface by their bulky nonconductive molecules.6 But both of these mechanisms seem to be invalid in case of electrochemical sensors based on conductive MIP films. In our previous studies, we demonstrated that a drop in the DPV current, caused by the appearance in a solution of an analyte, at conductive MIP film-coated electrodes might originate not from hindering the diffusion of the redox probe through the film but from changes in electrochemical properties of the film itself 7. Suppose the redox probe diffusion through the MIP film is not a decisive parameter for the faradaic current involving. Then, in the, e.g., DPV, determinations of electroinactive analytes at conductive MIP film-coated electrodes, this diffusion may be eliminated. For that the redox probe could be immobilized inside the MIP film matrix. Herein, we propose to deposit a self-reporting MIP film and apply it for fabrication of the selective electrochemical sensor determining the target analyte in the redox probe free test solutions. For that purpose, a ferrocene redox probe was covalently immobilized in a bis-bithiophene polymer molecularly imprinted with the p-synephrine template. Simultaneously, this polymer was deposited on the Pt electrode as a thin film. After the template extraction from the film, the analyte was determined with differential pulse voltammetry (DPV) in a redox probe free solution. That was possible because the internal ferrocene redox probe generated the DPV analytical signal. The thickness and morphology of the film were crucial for the sensor's performance. The mechanism of this redox self-reporting MIP film-based chemosensor was examined with electrochemical methods, simultaneous piezomicrogravimetry and electrochemistry at an electrochemical quartz crystal microbalance, and surface plasmon resonance spectroscopy. The devised chemosensor was applied for selective p-synephrine determination in a concentration range of 2.0 to 75 nM. References Cieplak, M.; Kutner, W., Artificial biosensors: How can molecular imprinting mimic biorecognition? Trends Biotechnol. 2016, 34 (11), 922-941. Uzun, L.; Turner, A. P. F., Molecularly-imprinted polymer sensors: realising their potential. Biosens. Bioelectron. 2016, 76, 131-144. Huynh, T.-P.; Sharma, P. S.; Sosnowska, M.; D'Souza, F.; Kutner, W., Functionalized polythiophenes: Recognition materials for chemosensors and biosensors of superior sensitivity, selectivity, and detectability. Prog. Polym. Sci. 2015, 47, 1-25. Yoshimi, Y.; Narimatsu, A.; Nakayama, K.; Sekine, S.; Hattori, K.; Sakai, K., Development of an enzyme-free glucose sensor using the gate effect of a molecularly imprinted polymer. J. Artif. Organs 2009, 12 (4), 264-270. Sharma, P. S.; Garcia-Cruz, A.; Cieplak, M.; Noworyta, K. R.; Kutner, W., 'Gate effect' in molecularly imprinted polymers: the current state of understanding. Curr. Opin. Electroche. 2019, 16, 50-56. Moreira, F. T. C.; Dutra, R. A. F.; Noronha, J. P. C.; Fernandes, J. C. S.; Sales, M. G. F., Novel biosensing device for point-of-care applications with plastic antibodies grown on Au-screen printed electrodes. Sens. Actuators, B 2013, 182, 733-740. Lach, P.; Cieplak, M.; Majewska, M.; Noworyta, K. R.; Sharma, P. S.; Kutner, W., "Gate Effect" in p-Synephrine Electrochemical Sensing with a Molecularly Imprinted Polymer and Redox Probes. Anal. Chem. 2019, 91 (12), 7546-7553. Figure 1

An Upgraded "Two-in-One" Strategy toward Highly Crystalline Covalent Organic Frameworks.

A highly crystalline bicarbazole-based covalent organic framework (BCzP-COF) was synthesized via an upgraded "two-in-one" strategy by the self-polycondensation of A2 B2 monomer with two neopentyl acetal and two amine groups. Such a strategy is propitious to afford higher crystallinity, larger special surface areas and better morphology than that of using unprotected monomer with free aldehydes and amines. Additionally, the off-white powder of BCzP-COF could serve as acidichromism sensor with a significant color change. Intriguingly, the conductivity of the protonated BCzP-COF can improve by six orders of magnitude compared to that of the pristine samples. This work has the potential to lead to bicarbazole-functional materials for chemosensors and electronic devices.

An Experimental Complex for High-Performance Screening of Photoluminescent Chemosensor Materials

An experimental complex is described for conducting high-performance screening of the functional characteristics of photoluminescent chemosensor materials (CSMs) intended for determining volatile organic compounds in the gas phase and optimizing the characteristics of matrix sensors based on CSMs in multicomponent vapor-gas mixtures. The complex combines a system for the continuous generation of multicomponent gas-vapor mixtures, which allows automated control of the composition of the mixture and the concentration of its components in the range from 0.01 mg/m3 to saturated vapors, and a system for exciting and recording the photoluminescence spectra of samples. The experimental data obtained in the study of fluorescent responses of a set of CSM based on boron dibenzoylmethanatoboron difluoride (DBMBF2) in mixtures of aromatic substances.

Exploring Colorimetric Real-Time Sensing Behavior of a Newly Designed CT Complex toward Nitrobenzene and Co2+: Spectrophotometric, DFT/TD-DFT, and Mechanistic Insights.

An exceptionally unique, easy-to-prepare, and economic charge transfer complex (CTC), [(IMH)+(PA)−], was synthesized as a highly selective real-time colorimetric chemosensor material for nitro explosive nitrobenzene (NB) and Co2+ ion. Co2+ and NB are highly potential toxic and hazardous beyond the exposure limits and also classified as carcinogens (group 2B) by IARS and United States Environmental Protection Agency. Unusual sensing ability with appreciatively low detection limits of 0.114 and 0.589 ppb for NB and Co2+ ion, respectively, in the aqueous medium of dimethyl sulfoxide has been reported for the first time among this class of complexes reported so far. The mechanism of the tremendous sensing behavior of this material as chemosensor was ascertained by static quenching mechanism, Dexter electron transfer, and Forster resonance energy transfer dynamic quenching mechanism, which was supported by spectral overlapping and density functional theory (DFT) (B-3LYP/def2-SVP) calculations. Real-time colorimetric sensing behavior of chemosensor was demonstrated by the naked eye test and prestained paper Co2+ strip test. Job’s plot and comparative Fourier transform infrared (FTIR) study between CTC and CTC–Co2+ complex revealed the coordination mode between CTC and Co2+ ion and 2:1 stoichiometry. This sensing material [(IMH)+(PA)−] was synthesized with donor imidazole (IM) and acceptor picric acid (PA), and its characterization was achieved by experimental (single-crystal X-ray diffraction, thermal gravimetric analysis–differential thermal analysis, FTIR, and UV–vis studies) and theoretical methods [DFT/TD-DFT calculations, comparing experimental–theoretical data and obtaining MEP map along with electronic energy gap of HOMO → LUMO (ΔE = 3.545 eV) and Hirshfeld surfaces analysis]. The SC-XRD confirms the composition and bonding features, which show hydrogen bond via N+–H···O– between IM and PA. This N+–H···O– interaction plays a significant role in Co2+ binding, proving this method of synthesizing CTC as a chemosensor to be a novel approach.

Synthesis of phosphorescent iridium(III) complex containing carbazole and its sensing property towards nitro-aromatic compounds

The phosphorescent Ir(III) complexes are very promising materials for optical chemosensors. In this letter, we report the synthesis of a yellow emissive phosphorescent iridium(III) complex (PFBHC)2Ir(acac) containing carbazole and its application for nitro-aromatic explosives detection. (PFBHC)2Ir(acac) displayed a high photoluminescence (PL) quantum yield, and the PL quenching tests indicate sensitive detection towards kinds of nitro-aromatics (e.g. PA, TNB, DNP, TNT, DNT) with moderate Stern-Volmer quenching constants, based on a photo-induced charge transfer process. In addition, the paper strip tests of (PFBHC)2Ir(acac) with obvious quenching effect towards low concentration of PA or TNB demonstrate a good potential as solid nitro-aromatics sensor.

Dual Sensing Performance of 1,2-Squaraine for the Colorimetric Detection of Fe3+ and Hg2+ Ions.

A simple 1,2-squaraine based chemosensor material (SQ) has been reported to show dual sensing performance for colorimetric detection of Fe3+ and Hg2+ ions. Compared to common instrumental analysis, this method could provide fast and direct detection though colorimetric changes by the naked eye. The sensor has shown excellent selectivity over the other metal ions by tuning different solvent environments. The detection limit for Fe3+ could reach to 0.538 μM, which was lower than that in the environmental agency guideline (U.S. Environmental Protection Agency, U.S. EPA) in drinking water. And for Hg2+ detection, the limit was calculated as 1.689 μM in our case. A 1:1 binding mode between SQ–Fe3+ and SQ–Hg2+ ion were evidenced by Job’s plot measurement and IR analysis. The proposed different binding mechanisms were also supported by Density Function Theory (DFT) calculation. All these findings provide a unique material and a simple, facile, and low cost colorimetric method for dual metal ions analysis and have shown preliminary analytical applications in industrial water sample analysis.

Selective and sensitive morpholine-type rhodamine B-based colorimetric and fluorescent chemosensor for Fe(III) and Fe(II)

The development of chemosensor materials is crucial for the early detection of hazardous materials, such as heavy metal ions and infectious viruses. In this study, three rhodamine B (RhB) derivatives (referred to as Rh-OS, Rh-OO, and Rh-SO) bearing a morpholine-type 6-membered ring as colorimetric, fluorescent sensors were synthesized, and fluorescence responses to various metal ions (Fe3+, Fe2+, Pb2+, Cr6+, Ce2+, Mn2+, Cd2+, Hg2+, K+, Na+, Mg2+, Li+, Ca2+, As3+, Co2+, Cu2+, Ni2+, and Zn2+) were investigated. Rh-OS, Rh-OO, and Rh-SO exhibited high sensitivity to Fe2+ and Fe3+, with the formation of a 1:1 (ligand: metal) complex, as evidenced by the UV–vis absorption and photoluminescence spectra. Luminescence turn-on was explained by the transfer of resonance energy from the morpholine-type moiety to the RhB framework. In addition, the selectivity of Fe3+ and Fe2+ was evaluated by 2D and 3D photoluminescence imaging.

Synthesis and characterization of S,N-heteroacenes by Bischler-Napieralski reaction

Bischler-Napieralski cyclization has been successfully employed to prepare planar S,N-heteroacenes (SNHs) with the analogue structures to 1,10-phenanthroline. The opto-/electrical properties and the packing modes of these S,Nheteroacenes were examined, which were dependent on the structure of the fused groups. SNH-based copolymers with high molecular weight and good solubility in common organic solvents or water have been synthesized by Suzuki-Miyaura- Schlüter polycondensation. The photophysical property studies revealed that the copolymers may be a promising chemosensor material.

Preparation of chemosensor materials based on silica nanoparticles with covalently anchored fluorophores by inkjet printing

Samples of sensor layers containing a mixture of spherical silica gel microparticles and spherical macromolecular silica sol nanoparticles have been prepared by inkjet printing. The average diameter of microparticles is 5 μm; nanoparticles about 100 nm in diameter contain covalently anchored fluorophore, dibenzoylmethane boron difluoride (DBMBF2), on the surface. The microstructure of the layers is shown to considerably affect the availability of the fluorophore indicator for gas-phase analyte molecules of the methylbenzene group. The sensitivity of the sensor layers is shown to reach 0.5 ppm with a response time of about 100 s.

Thiophene-Fused 1,10-Phenanthroline and Its Conjugated Polymers

A novel type of π-extended 1,10-phenanthroline, specifically with fused thiophene groups at the less exploited 3-, 4-, 7-, and 8-positions of the phenanthroline ring, and its conjugated polymers were designed and synthesized. The current developed route is based on the Bischler–Napieralski cyclization of the (1,2-phenylene)diamide precursor, which offers a facile and versatile strategy for preparing soluble and well-defined 1,10-phenanthroline derivatives and their analogues. High molecular weight poly(phenanthroline-co-fluorene)s with good solubility in common organic solvents or water were prepared by palladium-catalyzed Suzuki–Miyaura–Schlüter polycondensation. The optical responsive properties of these thiophene-fused 1,10-phenanthroline-containing polymers have demonstrated these polymers could be a good candidate for potential applications as luminescent chemosensor materials thanks to the specific repeating unit along the backbone.

Nanofibrous and Graphene-Templated Conjugated Microporous Polymer Materials for Flexible Chemosensors and Supercapacitors

Conjugated microporous polymers (CMPs) are usually obtained as amorphous or semicrystalline powders. Their insolubility and nonprocessability are considered as key bottlenecks that impede CMP applications. In this study, light-emitting, nanofibrous films were fabricated by electrospinning CMP/poly(lactic acid) (PLA) mixtures. The resulting nanofibrous films show a high flexibility combined with high porosity and surface-area-to-volume ratios. The CMP-based nanofibrous films have been used as sensitive sensors in the detection of nitroaromatic and benzoquinone vapors as well as oxidizing metal ions. Moreover, 4-iodophenyl-substituted graphene sheets were used as templates for growing CMP/graphene sandwiches. The graphene-based CMP (G-CMP) sandwiches are characterized by high surface areas and aspect ratios. Furthermore, hierarchically porous two-dimensional carbon nanosheets were obtained by pyrolysis of these carbon-rich G-CMP hybrids. The resulting carbon nanomaterials show excellent supercapacitor behav...

Vapochromic Copper (I) Pyrazolate Complex Materials for Phosphorescent Chemosensors of Ethanol

Here chemosensor materials of trinuclear copper (I) pyrazolate complexes have been successfully synthesized and isolated using two types of 3,5-dimethyl and 4-(3,5-dimethoxybenzyl)-3,5-dimethyl pyrazole ligands. Upon excitation at 280 nm, the resulting trinuclear 3,5-dimethyl copper (I) pyrazolate complex (complex A) and trinuclear 4-(3,5-dimethoxybenzyl) copper (I) pyrazolate complex (complex B) showed emission bands centered at 590 and 604 nm, respectively. These results were in good agreement with their greenish-white powders and it is characteristic of phosphorescent metal complexes from the weak Cu (I)-Cu (I) metallophilic interaction. Upon direct or stepwise exposure to ethanol vapor with series of concentrations (12.5, 25, 50, 100, 150 and 200μL in 22 mg of chemosensor), the emission of chemosensor complex A was not shifted even after 1 d. Interestingly, chemosensor complex B showed gradually changes in both emission band with shifting from 602 to 552 nm and color with changing from orange to green under Ultra-violet (UV) hand lamp (254 nm) at the dark room due to the attachment of benzyl ring to the pyrazole ligand. This positive response for chemosensor complex B was reversible; hence, this optical phosphorescent material can be used for developing vapochromic sensors of ethanol.

Multifunctional Periodic Mesoporous Organosilicas for Biomolecule Recognition, Biomedical Applications in Cancer Therapy, and Metal Adsorption

AbstractThis paper reports a new approach towards the construction of a multifunctional periodic mesoporous organosilica (PMO), which integrates a range of advantages, such as mesoporous structural order, selective nucleobase‐recognition properties, stimuli‐responsive site‐specific delivery of anticancer agents to cancer tissues, and Cu2+ adsorption, into a single entity. First, the appropriate organic‐functional‐receptor precursor was synthesized by a chemical process and used to fabricate a multifunctional pyridine‐containing PMO material (DMPy‐PMO) by a hydrolysis and condensation route. The designed organic–inorganic hybrid mesoporous silica chemosensor showed an intrinsic selective recognition of nucleobase, specifically thymidine, through multipoint hydrogen‐bonding interactions with suitably arrayed receptor sites loaded into the rigid silica framework. An in vitro cytotoxicity test showed that the designed chemosensor materials have good biocompatibility and, therefore, could be promising candidates for the delivery of a range of therapeutic agents. Confocal laser scanning microscopy (CLSM) confirmed that the material can be internalized effectively by cancer cells (MCF‐7 cells). In addition, the DMPy‐PMOs showed efficient Cu2+ ion removal capacity at pH 5.0 with significantly high levels of adsorption (0.95 mmol g–1). These results suggest that the prepared multifunctional PMO hybrid has potential use as a smart material for a range of applications, such as biomolecule recognition, biomedical applications, and as an efficient adsorbent for the removal of metal ions.

Synthesis and Optical Properties of Novel Chemosensor Based on Rhodamine 6G

The opto-functional materials have been developed as a promising research topic toward the end uses for optical materials and applications. The attractive area in this part was the design of sensor molecules for detecting harmful environmental factors. These harmful factors impart undesired effects on wide range of chemical and biological phenomenon. In this context, many researchers have studied luminescence chemosensor materials. These sensor molecules showed optical signals such as color or fluorescence change by detecting harmful environmental factors. In this study, the novel fluorescence chemosensor 1 has been designed and synthesized through reaction of rhodamine 6g hydrazide and 2-hydroxy-1-naphthaldehyde. The chemosensor 1 had been analyzed by UV-Vis and fluorescence spectrophotometer. We found that this chemosensor 1 has 'off-on' and dual type sensing properties toward <TEX>$Cu^{2+}$</TEX> and <TEX>$Mg^{2+}$</TEX>.