Thiol-functionalized Mesoporous Silica Research Articles

Thiol-functionalized mesoporous silica-embedded AuNPs with highly sensitive substrates for surface-enhanced Raman scattering detection

Surface-enhanced Raman spectroscopy (SERS) provides a fast, simple, and label-free approach that can directly detect various analytes attached to SERS substrates and provide qualitative and quantitative information based on the SERS spectra of the analyte. The signal enhancement provided by noble metal particles allows us to achieve high sensitivity and good stability even at low concentrations in water quality testing. Over the past decade, SERS has become increasingly popular in the detection field, highlighting its significant application potential. However, the signal enhancement of single AuNPs is inferior to that of AgNPs, but we can achieve an overall enhancement by uniformly arranging multiple AuNPs. The hot-spot effect, which is crucial for Raman signal enhancement, occurs only when NMNPs are within a specific distance. However, when noble metal particles come into contact with each other, the enhancement effect of the hot spot disappears. Therefore, in this study, AuNPs@MPS-SH substrates with surface-enhanced Raman scattering (SERS) activity were successfully synthesized by immobilizing AuNPs on thiol-functionalized mesoporous silica (MPS-SH). MPS nanospheres with tailored pore size and surface-bound -SH groups were synthesized for the controlled embedding of Au nanoparticles (AuNPs). By adjusting the ratio of reactants, uniform AuNP dispersion and strong MPS-AuNP interactions were achieved. This optimized structure creates localized surface plasmon resonance (LSPR) hotspots, significantly enhancing the surface-enhanced Raman scattering (SERS) effect for ultrasensitive analyte detection. Transmission electron microscopy (TEM) revealed that the average diameter of MPS nanoparticles is 260 nm, with a pore size of 8 nm. Optimal Raman enhancement was achieved at an AuNPs concentration of 2.6 × 1018 particles/mL. The lowest detection limit concentration for Rhodamine 6G was below 10−6 M, while for uremic toxin (urea) it was below 10−3 M. The ability to directly detect low concentrations by mixing with the analyte demonstrates the ultra-high sensitivity and label-free detection potential of this study in the fields of water quality and disease detection.

Synergistic chemo-photothermal therapy using gold nanorods supported on thiol-functionalized mesoporous silica for lung cancer treatment

Cancer therapy necessitates the development of novel and effective treatment modalities to combat the complexity of this disease. In this project, we propose a synergistic approach by combining chemo-photothermal treatment using gold nanorods (AuNRs) supported on thiol-functionalized mesoporous silica, offering a promising solution for enhanced lung cancer therapy. To begin, mesoporous MCM-41 was synthesized using a surfactant-templated sol–gel method, chosen for its desirable porous structure, excellent biocompatibility, and non-toxic properties. Further, thiol-functionalized MCM-41 was achieved through a simple grafting process, enabling the subsequent synthesis of AuNRs supported on thiol-functionalized MCM-41 (AuNR@S-MCM-41) via a gold-thiol interaction. The nanocomposite was then loaded with the anticancer drug doxorubicin (DOX), resulting in AuNR@S-MCM-41-DOX. Remarkably, the nanocomposite exhibited pH/NIR dual-responsive drug release behaviors, facilitating targeted drug delivery. In addition, it demonstrated exceptional biocompatibility and efficient internalization into A549 lung cancer cells. Notably, the combined photothermal-chemo therapy by AuNR@S-MCM-41-DOX exhibited superior efficacy in killing cancer cells compared to single chemo- or photothermal therapies. This study showcases the potential of the AuNR@S-MCM-41-DOX nanocomposite as a promising candidate for combined chemo-photothermal therapy in lung cancer treatment. The innovative integration of gold nanorods, thiol-functionalized mesoporous silica, and pH/NIR dual-responsive drug release provides a comprehensive and effective therapeutic approach for improved outcomes in lung cancer therapy. Future advancements based on this strategy hold promise for addressing the challenges posed by cancer and transforming patient care.

Amine- and thiol-functionalized SBA-15: Potential materials for As(V), Cr(VI) and Se(VI) removal from water. Comparative study

SBA-15 type materials functionalized with 3-aminopropyltriethoxysilane (APTES), N-[3-(trimethoxysilyl)propyl]-ethylenediamine (TMPED) and 3-mercaptopropyltrimethoxysilane (MPTMS) have been compared for their ability to adsorb arsenic(V), chromium(VI) and selenium(VI) oxyanions from an aqueous solution. The effects of pH and contact time on the adsorption of As(V), Cr(VI) and Se(VI) were studied. Adsorption was very fast, a maximum of 3 min was required to reach adsorption equilibrium. Under the optimal pH values the maximum static adsorption capacities were as follows: As(V)/SBA-APTES – 36 mg g−1, As(V)/SBA-TMPED – 24 mg g−1, Cr(VI)/SBA-APTES – 51 mg g−1, Cr(VI)/SBA-TMPED – 55 mg g−1, Cr(VI)/SBA-MPTMS- 55 mg g−1, Se(VI)/SBA-APTES – 79 mg g−1, Se(VI)/SBA-TMPED – 78 mg g−1, Se(VI)/SBA-MPTMS – 31 mg g−1. XPS studies proved that adsorption of As(V), Cr(VI) and Se(VI) onto amine- and thiol-functionalized SBA-15 leads to the reduction of adsorbate and various chemical changes of sorbent functional groups. It was shown that the 0.5 mol L−1 chloride solution prevents the adsorption of As(V) and Cr(VI) onto SBA-APTES and SBA-TMPED materials, and only slightly hinders adsorption of Se(VI). Nitrate ions have a lesser influence on the adsorption of As(V), Cr(VI) and Se(VI) than chloride ions. The application of HNO3 and HCl of various concentrations do not allow to quantitatively desorb As, Se and Cr from studied sorbents. The results suggest that amine- and thiol-functionalized mesoporous silica could be used as effective adsorbents for the removal of As(V), Cr(VI) or Se(VI) from aqueous solution.

In vitro speciation of molybdenum in human biological samples based on thiol functionalized mesoporous silica nanoparticles and hexyl-methylimidazolium tris-pentafluoroethyl-trifluorophosphate

Molybdenum (Mo) ions enter to human body from the diet or drinking waters and have a potentially toxic effect on humans. The thiol-functionalized mesoporous silica nanoparticles (HS-MSNPs) were used for determination and speciation of Mo (II, VI) in human biological samples by dispersive ionic liquid-micro-solid phase extraction (DIL-μ-SPE) coupled to electrothermal atomic absorption spectrometry (ET-AAS). Firstly, the mixture of HS-MSNPs (15 mg), the hydrophobic ionic liquid (1-Hexyl-3-methylimidazolium tris(pentafluoroethyl) trifluorophosphate; [HMIM][T(PFE)PF3]) and acetone injected into 10 mL of human blood and serum samples. After shaking for 5 min, the Mo(II) and Mo(VI) ions were extracted with the thiol group of MSNPs at pH 6 and 2, respectively, and collected through IL at the bottom of the conical tube by centrifuging. Then, the MO(II,VI) ions were back-extracted from HS-MSNPs with elent based on changing pH, and remained solutions were determined by ET-AAS after dilution with DW up to 0.5 mL, separately.

Removing Pb2+ by Adsorption over Thiol-Functionalized Mesoporous Silica

A thiol-functionalized HMS mesoporous silica was synthesized with thiolsilane. FTIR characterization suggests that thiol group has been anchored on the surface of HMS. SH-HMS performs better than HMS in adsorption of lead ion from water. The adsorption ratio on SH-HMS monotonously increases with adsorption time, which is beyond 95.5% after 5 min of adsorption time and be close to the equilibrium state. It decreases with pH value while increases with adsorbent dosage. Furthermore, the increment of lead initial concentration leads to decrease the adsorption ratio while increase the adsorption quantity. Adsorption ratioof 100 % can be obtained under following conditions: pH 6, 30 min of adsorption time, 8 g L–1 of adsorbent dosage, and 40 mg L–1 of initial lead concentration. The relationship between the adsorptive quantity and equilibrium adsorption concentration is in good accordance with both of the Langmuir isotherm model and the Freundlich model.

Facile one-pot synthesis of thiol-functionalized mesoporous silica submicrospheres for Tl(I) adsorption: Isotherm, kinetic and thermodynamic studies.

For the first time, thiol-modified mesoporous silica submicrospheres (TMS-SMSs) have been applied to remove extremely high toxic Tl(I) ions from aqueous solution by an adsorption approach. TMS-SMSs as a silica-based material is basically environmentally benign, with combined advantages of porosity and functionality. XRD measurement and TEM images clearly exhibited a parallel arrangement of mesopores in TMS-SMSs with a combination of both semi-long-range ordering and wormhole-like motif structures. The batch adsorption of Tl(I) onto TMS-SMSs showed a typical Langmuir adsorption isotherm (among various non-linear isotherm models) with the maximum adsorption capacity of 452.8 mgg-1. TMS-SMSs show a fast adsorption rate, and pseudo-second-order kinetic model provides the best correlation between experimental data. The thermodynamic constants indicated that the adsorption of Tl(I) ions was an endothermic (ΔH° = 24.80 kJ mol-1), entropy driven (ΔS° = 0.161 kJ mol-1K-1), and spontaneous process (ΔG° = 23.15-27.95 kJ mol-1). This study provides an exciting opportunity to advance our knowledge of functionalized-mesoporous silica submicrospheres as a promising adsorbent for the removal of toxic Tl(I) ions from aqueous solution using adsorption approach.

Synthesis of thiol-functionalized mesoporous silica nanoparticles for adsorption of Hg2+ from aqueous solution

Development of new adsorbents for efficient capturing of mercury (Hg(II)) ions from aqueous solution is of significant importance in environmental area. In this work, mesoporous silica nanoparticles with different morphologies (flower-like nanospheres with wrinkles, nanoparticles with concavities and sunken nanovesicles) were prepared and functionalized with 3-mercaptopropyltrimethoxysilane (MPTS). The as-prepared materials were characterized by different technics and applied for Hg2+ removal from aqueous solution. The sample with flower-like nanospheres morphology exhibited highest surface area and pore volume among the three silica samples, and the corresponding S-H groups functionalized nanospheres showed the highest adsorption capacity of 479 mg/g and fast adsorption rate for Hg2+. The isotherm and kinetics data fitted well with the Langmuir isotherm and the pseudo-second-order kinetics model, respectively. Furthermore, the above adsorbent could be easily regenerated and the regeneration efficiency could remain 94% up to three cycles of the regeneration.

Low cost thiol-functionalized mesoporous silica, KIT-6-SH, as a useful adsorbent for cadmium ions removal: A study on the adsorption isotherms and kinetics of KIT-6-SH

In this study, we have prepared and characterized 3‑(trimethoxysilyl)‑1‑propanethiol functionalized mesoporous silica, KIT-6-SH, then investigated its efficacy in the sense of cadmium removal. KIT-6-SH was characterized by FT-IR spectroscopy, TGA, X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). The obliteration of cadmium ions by KIT-6-SH was found to be mainly governed by surface adsorption. The elimination of cadmium ions from aqueous solutions was conducted using a batch method. Factors including the initial metal ion concentration, pH, and contact time were determined to be influential parameters on the sorption process. The sorption isotherm data were clearly described by the Langmuir model and maximum adsorption capacity for KIT-6-SH was 85 mg g−1. Moreover, a pseudo-second-order kinetic model was found to govern the sorption kinetics. According to these findings, it can be concluded that KIT-6-SH is well suited for the efficient and selective removal of cadmium ions from aqueous solutions.

Palladium adsorption and preconcentration onto thiol- and amine-functionalized mesoporous silicas with respect to analytical applications

Abstract Amine- and thiol-functionalized mesoporous SBA-15 silicas were synthesized, characterized and then applied to solid phase extraction of palladium from digested environmental samples (soil and road dust) with subsequent determination by slurry sampling graphite furnace atomic absorption spectrometry (GFAAS). The SBA-15 material was synthesized by the template method and fully characterized by a broad range of instrumental techniques. Functionalized samples were able to adsorb Pd(II) ions quickly and quantitatively from a wide range of concentrations and pH values. The adsorption uptakes were as high as 190 mg g−1 and 68 mg g−1, for thiol- and amine-modified silicas, respectively. GFAAS was used for fast and simple determination of palladium preconcentrated on the silica matrix. The proposed combination of Pd(II) preconcentration and Pd-loaded sorbent slurry sampling GFAAS technique application allowed reaching an Pd(II) enrichment factor of 25 and LOD of 4.8 ng g−1.

Preparation and analytical application of novel thiol-functionalized solid extraction matrices: From mesoporous silica to hybrid monolithic capillary column

A comprehensively comparative study of thiol-functionalized mesoporous silica and organic-inorganic hybrid monolithic column was reported, aiming at the separation and enrichment of inorganic arsenic. Thiol-functionalized mesoporous silica was synthesized based on the one-step co-condensation method. At the same time, a novel thiol-functionalized organic-inorganic hybrid monolithic column was synthesized using an unconventional ternary weak basic solvent system via one-step sol-gel process. The approach to prepare monolithic column through mild condition remarkably improved delamination phenomenon of thiol-functionalized hybrid monolithic column easily caused by conventional methods. As(III) can be selectively uptaken by the hybrid monolithic column and homemade syringe-based solid phase extraction device containing mesoporous silica through chelation in a wide range of pH, while As(V) cannot, and then the captured As(III) was eluted by 3% HNO3 (v/v) with 0.01 mol L−1 KIO3. Under the optimized conditions, the extraction recoveries were 91–102% and 93–103% for mesoporous silica and monolithic column, respectively. Although both two materials were ideal solid matrices for the removal and speciation analysis of As(III) in environmental waters, the monolith-based solid phase microextration protocol was more fast and reagent-saving than the other, which endued monolithic columns with more application prospects for trace elemental analysis and speciation. Even so, the exploration of mesoporous silica could efficiently pilot the synthesis of monolithic columns.

Efficient visible-light-driven depolymerization of oxidized lignin to aromatics catalyzed by an iridium complex immobilized on mesocellular silica foams

A novel Ir(ppy)2(bpy) complex-containing mesoporous cellular silica foams (Ir(ppy)2(bpy)-MCFs) was prepared by a facile thiol-ene click reaction between the prefabricated thiol-functionalized mesoporous cellular silica foams and vinyl-tagged [Ir(ppy)2(bpy)]PF6 complex. The elaborate Ir(ppy)2(bpy)-MCFs material possessed the large surface area (355 cm2/g), open foam-like mesoporous structure with 30 nm cell pore size and 3.0 nm window pore size. Importantly, it had the well-defined molecular configuration of Ir(ppy)2(bpy) active species. As expected, it exhibited excellent catalytic reactivity and selectivity in the visible-light-driven reductive depolymerization of oxidized lignin β-O-4 model compounds including p-hydroxyphenyl (H)-, guaiacyl (G)- and syringyl (S)-type units under the mild conditions. Meanwhile, it showed the comparable catalytic efficiency with the corresponding homogeneous [Ir(ppy)2(bpy)]PF6 catalyst. These high catalytic performances could be attributed to aerogel-like three-dimensional pore structure and high visible-light transparency, which efficiently decreased the mass transfer resistance and the photon propagation hindrance. Furthermore, it could be easily recycled and reused at least six times without the remarkable loss of catalytic activity.

Development of a Ru Nanoparticle Loaded Thiol Functionalized Meso Porous Silica Modified Screen Printed Au Electrode for Electrochemical Detection and Estimation of Glucose.

Here we report the development of a glucose sensor based on electrochemical detection. The working electrode was a screen printed Au electrode, which was modified with Ru nanoparticle loaded thiol functionalized mesoporous silica. This sensor demonstrated its capability of detecting and estimating glucose concentration in aqueous medium over a wide range of concentration with high sensitivity, durability and reproducibility.

Simple route to anchor silver nanoparticles into thiol-functionalized mesoporous silica: synthesis, characterization and electrochemical applications

This work describes an elegant route to synthesize silver nanoparticles (AgNPs) into thiol-functionalized mesoporous silica (TFS). The successful synthesis of AgNPs in TFS (Ag-TFS) is confirmed by spectroscopy and microscopy techniques. TEM images reveal the presence of distorted spherical shapes of AgNPs with 1–30 nm size in the TFS. Though the distribution of AgNPs is uniform throughout the TFS spheres, the size of the AgNPs varies. The electrocatalytic activity of Ag-TFS on the oxidation of nitrite is studied, and its determination is compared with the TFS based on differential pulse voltammetry (DPV). The Ag-TFS-coated glassy carbon (GC) electrode (GC/Ag-TFS) shows stable and superior electrochemical features for nitrite oxidation over the GC/TFS electrode as studied by DPV. The linear calibration range for nitrite determination at GC/Ag-TFS is found to be 1.0 µM–20.0 mM with a sensitivity of 73 µAmM−1 cm−2 and a detection limit of 0.5 µM.

Synthesis and application of thiolated mesoporous silicas for sorption, preconcentration and determination of platinum

Thiol-functionalized mesoporous silicas were synthesized by co-condensation of tetraethoxysilane (TEOS) and mercaptopropyltriethoxysilane (MPTES). All materials exhibit high values of specific surface area (456–857 m2/g), pore volume (0.5–1.3 cm3), and pore sizes (2.5–5.3 nm). These values gradually decrease with the increasing amount of MPTES. The obtained thiolated mesoporous silicas were used as sorbents of Pt(IV) species from water solution. The obtained materials exhibit an extremely good ability to remove Pt(IV) ions in the pH range 1–4. The highest adsorption capacity of platinum ions onto the thiolated mesoporous silica reached the value of 222 mg/g (1.14 mmol/g). The analytical applicability of the synthesized sorbents for Pt(IV) preconcentration was investigated and validated using the platinum reference materials. High accuracy of platinum determination was achieved which makes the obtained silicas very promising materials for the above mentioned application.

Thiol-Functionalized Mesoporous Silica for Effective Trap of Mercury in Rats

The chance of exposure to heavy metal for human being rises severely today due to the increasing water contamination and air pollution. Here, we prepared a series of thiol-functionalized mesoporous silica as oral formulation for the prevention and treatment of heavy metal poisoning. The successful incorporation of thiol was verified by the FTIR spectra. SBA15-SH-10 was used for the study as it is of uniform mesopores and fine water dispersibility. In simulated gastrointestinal fluid, the thiol-functionalized mesoporous silica can selectively capture heavy metal, showing a very high affinity for inorganic mercury (II). The blood and urine mercury levels of rats fed with a diet containing Hg (II) and material were significantly lower than those of rats fed with the metal-rich diet only. On the contrary, the mercury content in fecal excretion of the treatment group increased more than twice as much as that of the control group. This result indicated that SBA15-SH-10 could effectively remove mercury (II)in vivoand the mercury loaded on SBA15-SH-10 would be excreted out. Hence, SBA15-SH-10 has potential application in preventing and treating heavy metal poisoningviadigestive system.

The properties of mesoporous silica nanoparticles functionalized with different PEG-chain length via the disulfide bond linker and drug release in glutathione medium

In this paper, a novel drug-loaded material (MSNs-SS-PEG) was obtained by grafting the thiol-linked methoxy polyethylene glycol (MeOPEG-SH) onto the thiol-functionalized mesoporous silica nanoparticles (MSNs-SH) via the disulfide bond linker. In our designed experiment, three different chain lengths of PEG (PEG1000, PEG5000, and PEG1000-PEG5000) were used. The silica materials were characterized by Fourier transform infrared spectroscopy (FT-IR), dynamic light scattering, field emission scanning electron microscopy, transmission electron microscopy, nitrogen adsorption–desorption measurements, and X-ray diffraction. The morphology of the MSNs-SS-PEG was spherical with an average diameter of about 150 nm. Due to the covalent modification of hydrophilic MeOPEG, the MSNs-SS-PEG was coated by a thin polymer shell, showing stable and inerratic MCM-41 type mesoporous structure as well as high specific surface areas and large pore volumes. Moreover, the releases of doxorubicin hydrochloride (DOX) from these materials at 10 mM of glutathione were investigated. The PEG functionalization could effectively cap drugs in the mesoporous channels. The release of DOX from the MSNs-SS-PEGn revealed redox-responsive characteristic. The obtained results showed that the MSNs-SS-PEG might be promising drug delivery carrier materials, which could play an important role in the development of drug delivery.

Adsorption of Pb(II) and Cu(II) metal ions on functionalized large-pore mesoporous silica

Adsorption of copper and lead ions in aqueous solutions onto large-pore mesoporous silica materials functionalized with amino and mercapto groups and those with different morphologies including fiber-like, rod-like, and platelet was studied. The synthesized materials were characterized by techniques such as X-ray powder diffraction, nitrogen adsorption–desorption isotherms, scanning electron microscopy, and infrared spectra. Batch experiments were conducted to determine the adsorption processes. The equilibrium adsorption data agreed with Langmuir isotherms and revealed that four amino groups were required to form a stable surface complex with copper ions. Results indicated that initial adsorption rate onto platelet mesoporous adsorbent was rapid and faster than that of rod-like and fibrous morphologies due to its short channeling pores. Thiol-functionalized mesoporous silica adsorbents of all the morphologies have a better affinity for Pb2+ than the amino-mesoporous silica. In contrast, amino-mesoporous silica has a stronger affinity for Cu2+ compared to thiol-mesoporous silica. The optimal Pb2+ uptake on thiol-mesoporous silica was in solution with pH in 2–6, while the highest Cu2+ uptake on amino-mesoporous silica was at pH 5.

Сорбционные свойства мезопористых силикатов, функционализированных тиольными группами

Normal 0 false false false RU X-NONE X-NONE The synthesis and physico-chemical characteristics of thiol-functionalized mesoporous silicates MCM-41 and SBA-15 are described. The sorption properties of the materials with respect to noble metal ions, in particular palladium(II) from hydrochloric acid solutions have been studied. The materials obtained have been characterized using a complex of physical and chemical methods before and after functionalization. The evaluation of the sorption capacity of the obtained sorbents with respect to Pd(II) ions has been performed. Experimental results show high sorption activity of thiol-functionalized mesoporous silica /* Style Definitions */ table.MsoNormalTable {mso-style-name:Обычная таблица; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri,sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Times New Roman; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Times New Roman; mso-bidi-theme-font:minor-bidi;}

Activation of Aryl Chlorides in Water under Phase-Transfer Agent-Free and Ligand-Free Suzuki Coupling by Heterogeneous Palladium Supported on Hybrid Mesoporous Carbon

In this study, heterogeneous palladium catalysts supported on ordered mesoporous cobalt oxide–carbon nanocomposites were applied to the water-mediated Suzuki coupling reaction of chlorobenzene and phenylboronic acid and exhibited a high yield of biphenyl (49%) under mild reaction conditions free of phase-transfer agents and ligands. Product yields in the reaction of aryl chlorides containing electron-withdrawing groups attached to their benzene ring can reach approximately 90%. Thiol-functionalized mesoporous silica, which can trap soluble Pd species, was used to confirm the negligible leaching in solution and therefore heterogeneous reaction. This heterogeneous catalyst is stable, showing unobvious activity loss after 10 catalytic runs. Characterization by X-ray diffraction, transmission electron microscopy, X-ray photoelectron spectroscopy, X-ray absorption fine structure analysis, and N2 sorption techniques revealed intercalated CoO nanoparticles inside a carbon matrix with uniform mesopore sizes (∼3 n...

Functionalized mesoporous silica nanoparticles with mucoadhesive and sustained drug release properties for potential bladder cancer therapy.

The synthesis of a series of β-cyclodextrin modified mesoporous silica nanoparticles with hydroxyl, amino, and thiol groups was described. A comparison of their mucoadhesive properties and potential as a drug delivery system for superficial bladder cancer therapy was made. The thiol-functionalized nanoparticles exhibit significantly higher mucoadhesivity on the urothelium as compared to the hydroxyl- and amino-functionalized nanoparticles. This is attributed to the formation of disulfide bonds between the thiol-functionalized nanoparticles and cysteine-rich subdomains of mucus glycoproteins. An anticancer drug, doxorubicin, was loaded into the mesopores of the thiol-functionalized nanoparticles, and sustained drug release triggered by acidic pH was achieved. The present study demonstrates that thiol-functionalized mesoporous silica nanoparticles are promising as a mucoadhesive and sustained drug delivery system for superficial bladder cancer therapy.