Surfactant Cetyltrimethylammonium Bromide Research Articles

Surfactant-assisted carbon black for the electrochemical detection of endocrine disruptors

In this paper, the detection performances of carbon black (CB) for bisphenol A (BPA) can be greatly improved by using a surfactant of cetyltrimethylammonium bromide (CTAB). The cyclic voltammetry (CV) behavior of CTAB/CB for BPA can be improved 6 times, compared with CB. The hydrophobicity of the CTAB long-chain alkyl end can enhance the enrichment ability of BPA. Meanwhile, CB can act as an electron transmission bridge to accelerate the electrons transfer to external circuit, thereby improving the sensing signal of CTAB/CB sensor for BPA. The sensor displays a linear range of 0.04 to 0.99 μM, a low detection limit of 0.013 μM and has good reproducibility and selectivity. Finally, the sensor can also be successfully used for detecting BPA in actual samples including tap water and human urine.

Co-intercalation of CTAB favors the preparation of Ti3C2Tx/PANI composite with improved electrochemical performance

With the aid of the amphiphilicity and self-assembly ability of surfactant cetyltrimethylammonium bromide (CTAB), we demonstrate an effective method to increase the interlayer spacing of Ti3C2Tx nanosheets, which is beneficial to improve the performance of composites. Electrochemical tests show that Ti3C2Tx/polyaniline, treated by the co-intercalation of CTAB, exhibits higher redox activity and reversibility. A specific capacitance of 336 F·g−1 for as-prepared Ti3C2Tx/polyaniline composite is achieved at a current density of 0.5 A·g−1, 1.43 times greater than that of common Ti3C2Tx/polyaniline composite (236 F·g−1). Most importantly, a specific capacitance of 135 F·g−1 is retained when the current density increases to 16 A·g−1, much higher than 57 F·g−1 for the common composite. The superior charging/discharging capability is attributed to highly active and reversible polyaniline on Ti3C2Tx as well as the enlarged interlayer spacing, which will provide enough channel for the quick diffusion and migration of electrolyte ions.

A novel carbon nanosphere-based sensor used for herbicide detection

Bentazon (BTZ) is a post-emergence herbicide widely applied in different cultures. It is characterized by low adsorption and high solubility in water, which facilitates its penetration and contamination of aquatic environments. Human exposure to BTZ is responsible for numerous toxic effects and, therefore, it is of great importance to develop simple and efficient analytical methods capable of accurately detecting the presence of this herbicide in environmental samples. The present paper reports the development and application of a glassy carbon electrode modified with carbon nanosphere-based cross-linked chitosan film for the voltammetric determination of BTZ herbicide. The incorporation of cetyltrimethylammonium bromide surfactant into the supporting electrolyte solution helped enhance the voltammetric signal and the sensor repeatability. The use of chitosan film crosslinked with epicholorohydrin contributed toward improving the properties of the carbon nanospheres, including the electron transfer rate. A set of assays were conducted aiming optimizing the experimental parameters related to the supporting electrolyte composition (pH and surfactant concentration) and the square-wave voltammetry technique. Under optimized conditions and based on the application of the method proposed in the study, a linear concentration range of 1.99 to 65.4 μ mol L −1 was obtained, with limit of detection of 1.4 μ mol L −1 and sensitivity of 6.22 A mol −1 L cm −2 . The modified electrode presented good intra- (2.8%, n = 10 ) and inter-day (1.4%, n = 5 ) repeatability and high selectivity for bentazon. The optimized electroanalytical technique was successfully applied for the quantification of bentazon in environmental water samples (recoveries close to 100%). • Nanostructuring a glassy carbon surface for herbicide sensing purposes is reported. • A robust modified electrode is designed by immobilizing carbon nanospheres within a cross-linked chitosan film. • Adsorptive effects from bentazon oxidation products are reduced by applying cetyltrimethylammonium bromide. • The optimized voltammetric sensor was successfully applied for bentazon determination at environmental water samples.

Quasi-cubic hematite with exposed high-energy facets for ethanol gas detection

Facet engineering is a surface optimization strategy to improve the physical and chemical properties of metal oxide semiconductors. To exploit a facile method to fabricate high-performance ethanol sensing material and study the sensing mechanism, a quasi-cubic α-Fe2O3 was investigated, which with high-energy facets exposed. Cetyl trimethyl ammonium bromide (CTAB) surfactant was employed in the preparation of α-Fe2O3 to control the shape and size. The resulting Fe2O3 particles exhibited a mean size of 1.10 µm with high uniformity in size and shape. Additionally, the cubic structure can also optimize the electronic transmission path. Charge carriers are conducting between the cubes required to pass through the electron depletion layer on the surface, as the Fe2O3 particles are separated. Thus, the resistance change of the electron depletion layer significantly affected the overall conductivity. The DFT calculation also confirmed that the exposed facets had high adsorption energy to ethanol molecules, which validated the experimental results. The resulting α-Fe2O3 exhibited an excellent selectivity towards ethanol vapor with a response of 35.14–500 ppm ethanol gas, and the response and recovery times were 12 s and 41 s, respectively. Additionally, the sensing materials exhibited good long-term stability which maintained 92% of its initial response after 60 days, potential using in practical ethanol gas detection.

(−)-Hinokinin antimicrobial agents into functionalized mesoporous silica

The sol–gel process emerges as an interesting strategy to obtain hybrid materials (organic–inorganic materials), it takes place under mild conditions and can produce nanoparticles with different shapes and sizes, leading to composite materials with multifunctional properties. In this paper will describe the synthesis and characterization of the mesoporous silica obtained by the sol–gel process as well as their potential applications as antimicrobial agents, biological markers, odontology, and others. Highly ordered mesoporous silica has gained attention from scientists because it exhibits large specific area and pore volume as well as low density. The preparation of mesoporous silica matrixes via the sol–gel process by using the surfactant cetyltrimethylammonium bromide and the copolymer Pluronic P-123 as structure-driving agents. The results revealed that samples V and VII behaved the most efficiently. Log10 CFU/mL decreased by more than two digits for Candida albicans, Staphylococcus aureus, and Streptococcus mutans and was statistically significant for all the tested microorganisms. Therefore, this study demonstrated that the functionalized mesoporous silica is a viable antimicrobial agent when it is incorporated into dental acrylic resin.

Gold-Modified Micellar Composites as Colorimetric Probes for the Determination of Low Molecular Weight Thiols in Biological Fluids Using Consumer Electronic Devices

This work describes a new, low-cost and simple-to-use method for the determination of free biothiols in biological fluids. The developed method utilizes the interaction of biothiols with gold ions, previously anchored on micellar assemblies through electrostatic interactions with the hydrophilic headgroup of cationic surfactant micelles. Specifically, the reaction of AuCl4− with the cationic surfactant cetyltrimethyl ammonium bromide (CTAB) produces an intense orange coloration, due to the ligand substitution reaction of the Br− for Cl− anions, followed by the coordination of the AuBr4− anions on the micelle surface through electrostatic interactions. When biothiols are added to the solution, they complex with the gold ions and disrupt the AuBr4−–CTAB complex, quenching the initial coloration and inducing a decrease in the light absorbance of the solution. Biothiols are assessed by monitoring their color quenching in an RGB color model, using a flatbed scanner operating in transmittance mode as an inexpensive microtiter plate photometer. The method was applied to determine the biothiol content in urine and blood plasma samples, with satisfactory recoveries (i.e., >67.3–123% using external calibration and 103.8–115% using standard addition calibration) and good reproducibility (RSD < 8.4%, n = 3).

Adsorption complexes ‘zeolite–cationic surfactant’: properties and surface activity in a polymer composite material based on ultra-high-molecular-weight polyethylene

We investigated the adsorption of the cationic surfactant cetyltrimethylammonium bromide (CTAB) to zeolite from premicellar and micellar solutions, as well as some properties of the organically modified zeolite surface and the nature of its interfacial interaction with ultra-high-molecular-weight polyethylene (UHMWPE) in a UHMWPE-based polymer composite material (PCM). The formation mechanism of mono- and bimolecular adsorption layers of cetyltrimethylammonium cation and bromide anion to the clinoptilolite (Cli) surface was proposed, and the thermodynamic and kinetic characteristics of adsorption were determined. The surface texture of organically modified zeolite was studied by instrumental methods; the thermal stability limits of CTAB adsorption layers to zeolite surface and their decomposition behavior in inert and oxidizing media were established. The evaluation of the deformation and strength properties, the study of the supramolecular structure, and the calculation of the thermodynamic and kinetic parameters of the PCM crystallization process revealed that the filing with organically modified Cli increases the UHMWPE surface activity and improves their compatibility.

Evaluating Phospholipid-Functionalized Gold Nanorods for In Vivo Applications.

Gold nanorods (AuNRs) have attracted a great deal of attention due to their potential for use in a wide range of biomedical applications. However, their production typically requires the use of the relatively toxic cationic surfactant cetyltrimethylammonium bromide (CTAB) leading to continued demand for protocols to detoxify them for in vivo applications. In this study, a robust and facile protocol for the displacement of CTAB from the surface of AuNRs using phospholipids is presented. After the displacement, CTAB is not detectable by NMR spectroscopy, surface-enhanced Raman spectroscopy, or using pH-dependent ζ-potential measurements. The phospholipid functionalized AuNRs demonstrated superior stability and biocompatibility (IC50 >200 µg mL-1 ) compared to both CTAB and polyelectrolyte functionalized AuNRs and are well tolerated in vivo. Furthermore, they have high near-infrared (NIR) absorbance and produce large amounts of heat under NIR illumination, hence such particles are well suited for plasmonic medical applications.

Effect of surfactants on the transport of polyethylene and polypropylene microplastics in porous media

The transport of microplastics in porous media is attracting increasing attention. However, to date, research is limited to polystyrene microplastics. Meanwhile, surfactants can promote solid dispersion to form a stable suspension, possibly allowing microplastics to migrate when attached to a surfactant, which would increase the scope and degree of microplastic pollution, further endangering human health and the stability of the ecological environment. Therefore, in this study, the transport behavior of microplastics in porous media was explored in the presence of surfactants. Herein, polyethylene (PE) and polypropylene (PP) were evaluated while dispersed by two ionic surfactants: cationic surfactant-cetyltrimethylammonium bromide (CTAB) and anionic surfactant-sodium dodecylbenzenesulfonate (SDBS). The influence of different factors (surfactant concentration, ionic strength, pH, flow rate, and multivalent cations) on the transport of microplastics in porous media was explored via quartz sand packed-column experiments. Our experimental results show that the transport abilities of PE and PP increased with increasing surfactant concentration when the surfactant concentration was less than the critical micelle concentration (CMC). In the presence of CTAB and SDBS, physicochemical factors had different effects on the transport of microplastics mainly by controlling Zeta potential, advection diffusion and CMC. The mobility of PE and PP decreased with increasing ionic strength, cation valence and pH, and decreasing flow rate. However, the mobility of PE and PP under CTAB is much greater than that of PE and PP under SDBS, because quartz sand can absorb more CTAB molecules through electrostatic attraction to weaken the collision between microplastics and quartz sand. Further, the transport ability of PP was greater than that of PE under all conditions considered. Notably, the Extended-Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory formed by adding osmotic, elastic, and hydrophobic force could well described the migration behavior of microplastics in CTAB and SDBS well. This research highlights that surfactant has a significant impact on the transport ability of microplastics, and provides a comprehensive understanding of the migration and fate behaviors of microplastics affected by surfactants, which is necessary to prevent and reduce the environmental hazards of microplastics.

Fluid state transition mechanism of a ternary component aqueous solution based on dynamic covalent bond

Dynamic covalent bonds are reversible and responsive, the external environment can cause change of molecular configuration of the compound system, leading to changes in the microscopic morphology of the micelles, thereby achieving intelligent control of the fluid state. Therefore, this work used cationic surfactant cetyltrimethylammonium bromide (CTAB), 4-carboxybenzaldehyde (CB) and aniline (NA) to develop a ternary composite fluid state transition system with a molar ratio of 60:40:40 (CTAB/CB/NA). The bottle test method, rheology, 1H NMR, infrared spectroscopy, and Cryo-TEM were used to test and analyze the prepared ternary composite system to explore the effects of different dosages, temperatures and pH values on the rheological behavior of the system. The results show that when the pH increased from 3.13 to 7.25, the CTAB/CB/NA solution changed from a low-viscosity fluid to a transparent gel-like fluid, and the viscosity increased from 1 to 4.6 × 104 mPa·s, and the viscosity recovered when the pH decreased again. Therefore, the reversible changes in the viscoelasticity of the system can be triggered by changing the pH of the CTAB/CB/NA solution. This drastic change in rheological properties is attributable to the pH dependent ionization and formation of dynamic covalent bond CBNA, which is shown microscopically as the morphology of the system micelles changing from spherical micelles to worm-like micelles. The viscosity of the system decreases when the temperature increases, and the viscosity is almost zero when it reaches 50 °C. In addition, by adjusting the pH value, the CTAB/CB/NA solution can obtain more than 3 cycles of morphological changes from spherical micelles to worm-like micelles. This pH-responsive fluid state transition system can meet the viscosity requirements of the oil-displacing agent, and can also reduce the adsorption loss in the formation, and has more valuable research in the field of enhanced oil recovery.

Surfactant-assisted thermal hydrolysis off waste activated sludge for improved dewaterability, organic release, and volatile fatty acid production

The surfactant-assisted thermal hydrolysis pretreatment (THP) of waste activated sludge (WAS) was investigated, focusing on the effect of the surfactant addition on the results of sludge disintegration, dewaterability, organic release, and production of volatile fatty acids (VFAs) via fermentation. Typical anionic surfactant sodium dodecyl sulfate (SDS) and cationic surfactant cetyl trimethyl ammonium bromide (CTAB) were used for the THP experiments. The supernatant of the THP-treated sludge was anaerobically fermented to determine its potential VFAs yield. The results showed that the surfactant addition, particularly CTAB, enhanced the hydrolysis and organic solubilization of the sludge during THP. CTAB addition led to a 36% increase of dissolved organic and a 27% increase of VFAs production. For the THP-treated sludge with the surfactant addition, its dewaterability was also greatly improved. When the CTAB dosage increased from 0 to 0.10 g/g VSS, the minimum capillary suction time (CST) of the sludge decreased from 205 to 50 s/g TSS, and the sludge particles became smaller and less negative with the zeta potential changing from −12.4 to −8.2 mV. Analysis of extracellular polymeric substances (EPS) of the sludge revealed that the surfactant addition increased the sludge disintegration and organic dissolution during the THP process. The surfactant-assisted THP is shown to be a promising technology to enhance the WAS treatment for improved sludge dewaterability, waste reduction, and resource recovery.

Niosomes modified with cationic surfactants to increase the bioavailability and stability of indomethacin

Niosomes based on the nonionic surfactant Tween 80 and cholesterol and modified with cationic surfactants (cetyltrimethylammonium bromide or its carbamate-bearing analog) were formed by the thin film hydration method. Such a modification of niosomes provides an increase in their ζ potential up to 60 mV, whereas the hydrodynamic diameter of the particles is 100 nm and remains nearly unchanged when the content of the cationic surfactant is varied from 1 to 3 wt.%. The inclusion of anti-inflammatory drug indomethacin in niosomes makes it possible to exceed its limiting solubility in water by nearly 20 times. The dialysis method demonstrated an increase in the release time of the encapsulated drug by 1.5 times, which is a prerequisite for its prolonged action in biosystems. The study of the kinetics of indomethacin cleavage in alkaline media revealed that the niosomes enhanced the stability of the drug providing protection against hydrolytic destruction processes.

Effects of Conformational Variation on Structural Insights from Solution-Phase Surface-Enhanced Raman Spectroscopy.

Surface-enhanced Raman scattering (SERS) spectra contain information on the chemical structure on nanoparticle surfaces through the position and alignment of molecules with the electromagnetic near field. Time-dependent density functional theory (TDDFT) can provide the Raman tensors needed for a detailed interpretation of SERS spectra. Here, the impact of molecular conformations on SERS spectra is considered. TDDFT calculations of the surfactant cetyltrimethylammonium bromide with five conformers produced more accurate unenhanced Raman spectra than a simple all-trans structure. The calculations and measurements also demonstrated a loss of structural information in the CH2/CH3 scissor vibration band at 1450 cm-1 in the SERS spectra. To study lipid bilayers, TDDFT calculations on conformers of methyl phosphorylcholine and cis-5-decene served as models for the symmetric choline stretch in the lipid headgroup and the C═C stretch in the acyl chains of 1,2-oleoyl-glycero-3-phosphocholine. Conformer considerations enabled a measurement of the distribution of double-bond orientations with an order parameter of SC═C = 0.53.

Time dependent physicochemical changes of SDS-CTAB interacted self assembled vesicles: Ostwald ripening effect

It is found that oppositely charged surfactants SDS (sodium dodecyl sulfate) and CTAB (cetyltrimethylammonium bromide) at low concentrations (< critical micelle concentration or CMC) interact, and form self-assemblies (vesicles) in aqueous medium. Physicochemical characterization of the assemblies has been studied and reported. It has been found that the characteristic properties of these assemblies change with time. Investigations on the time dependent changes of such vesicles have been monitored over a period of three months. The properties studied were, turbidity, surface tension, conductance, size and shape, ζ-potential, fluorescence anisotropy and quenching of photosensitive dyes in them, thermodynamics of formation as well as toxicity. The surfactants (well below their CMCs) were mixed in different proportions making the final concentration of all at 0.6 mM. They were kept at temperature 303 K, and examined at different times (on the day of mixing, and subsequently after 10, 30, 60, and 90 days). It is known that by the phenomenon of Ostwald Ripening (OR) process, morphological changes in colloidal solution takes place; larger particles grow in size with time at the expense of smaller particles.We studied the OR effect on the physicochemical properties of the growing SDS-CTAB interacted vesicles in aqueous medium. Results and their documentations are herein presented. Such an elaborate study of vesicles with reference to OR process as per our knowledge was not done in the past.

Unravelling the role of Ag[sbnd]Cr interfacial synergistic effect in Ag/Cr2O3 nanostructured catalyst for the ammoxidation of toluene via low temperature activation of Csp3-H bond

An environmentally benign and cost-effective synthesis of benzonitrile is reported by direct oxidative cyanation of aromatic Csp3-H bonds of toluene over Ag(I)/Cr2O3 nanostructured catalyst. The catalyst was prepared by a hydrothermal route using cationic surfactant cetyltrimethylammonium bromide and was characterized by powder XRD, XPS, SEM, TEM, TGA, TPD, TPR, UV-visible, FTIR, XANES, and ICP-AES methods. Conjugal effect of Lewis plus Brønsted acidity coupled with AgCr interfacial synergistic interaction appears as detrimental for its high catalytic activity and selectivity (98.4%) for benzonitrile. In situ DRIFTS analysis suggested that the catalytic system proceeded via a reaction pathway explained by Mars-van Krevelen mechanism.

“Bi–O” vacancy-pairs induced photochromic behavior in Bi2WO6 ultrathin nanosheets

Developing cheap and efficient materials for enhancing the photochromic performance upon visible or solar light irradiation is a hot-topic in the field of solar energy conversion. However, few inorganic photochromic materials can provide satisfying applications due to their low coloring and bleaching efficiency as well as slight color change. Here, we synthesized the bismuth tungstate (Bi2WO6) ultrathin nanosheets with the thickness of 1.29 nm via co-precipitation-hydrothermal method using cetyltrimethylammonium bromide (CTAB) surfactant. The prepared ultrathin nanosheets show the similar crystalline structure but a narrowed band gap of 2.73 eV, as compared with the 2.86 eV of pristine Bi2WO6. Additionally, the numerous [WO6–xBr2x] species and abundant “Bi–O″ vacancy pairs on the surface can serve as active sites that suppress the recombination of photogenerated electron-hole pairs and capture the photogenerated electrons to form the color trapping centers. As a result, Bi2WO6 ultrathin nanosheets exhibit excellent photochromic behavior upon solar light irradiation (coloring time of 5 s) and under dark atmospheric treatment (bleaching time of 35 min) compared with WO3-based photochromic materials (coloring time of 20–60 min and bleaching time of 3 h days).

Investigating thermodynamic, acoustic and spectroscopic parameters of rutin trihydrate with cationic surfactant CTAB in hydro-ethanolic solvent systems

The research work represents thermodynamic, acoustic and spectroscopic analysis of a well known flavonoid; rutin trihydrate and cationic surfactant; cetyltrimethyl ammonium bromide (CTAB). The studies were conducted at five different temperatures (20 °C, 25 °C, 30 °C, 35 °C and 40 °C) and four different hydro-ethanolic concentrations (aqueous, 30% v/v, 70% v/v and absolute ethanol). The critical micelle concentration (CMC) values were obtained by studying the deviation in plots of specific conductivity (κ) with respect to change in CTAB concentration. These values were utilized to calculate various thermodynamic parameters viz. standard enthalpy change (ΔHom), standard entropy change (ΔSom) and standard Gibbs free energy change (ΔGom) of micellization. To further investigate the nature of interactions and flow properties; density (ρ), ultrasonic sound velocity (μ) and relative viscosity (ηr) of the system were measured. The obtained values were further used to calculate various acoustic parameters i.e. apparent molar volume (ϕv) and apparent molar compressibility (ϕk). Moreover, the FTIR and 1H NMR spectroscopic analysis was performed to confirm micelle formation and to determine the locus of flavonoid in micellar structure of surfactant. From the overall studies; electrostatic and hydrophobic interactions in the system were identified and enhanced flow properties were observed.

Migration behavior of Cr(VI) during the transformation of ferrihydrite-Cr(VI) co-precipitates: The interaction between surfactants and co-precipitates

Redistribution of Cr(VI) in ferrihydrite-Cr(VI) co-precipitates (Fh-Cr) was affected by co-precipitates transformation and coexisting substances. These effects were crucial for predicting the migration path of Cr(VI) in ferrihydrite-Cr(VI) co-precipitates. This work investigated the effects of the extensively used surfactants of anionic surfactant sodium dodecylbenzene sulfonate (SDBS) and cationic surfactant cetyltrimethylammonium bromide (CTAB) on the Fh-Cr transformation and redistribution of Cr(VI) for 10 days at different pH values (5.0, 7.5 and 9.0) and concentration of surfactants (0.5, 2.0 and 5.0 mM). The results showed that SDBS hindered the transformation of Fh-Cr to hematite and tended to transform into goethite. SDBS inhibited hematite formation by inhibiting the aggregation of Fh-Cr particles, and it enhanced the dissolution of Fh-Cr to facilitate the formation of goethite. Affected by the inhibition of Fh-Cr transformation, the process of Cr(VI) redistribution was delayed. CTAB did not affect the transformation of Fh-Cr, but allowed more Cr(VI) to enter the interior of iron minerals. When the surfactants were adsorbed on the Fh-Cr, SDBS decreased the adsorption of Cr(VI) by Fh-Cr, while CTAB increased the Cr(VI) adsorption. The findings of this study contribute to understand the effects of surfactants on the transformation of Fh-Cr and the behaviors of Cr(VI) during this process.

Impact of temperature and surfactant addition on milk foams

Abstract Milk is a complex colloidal solution. Knowledge of milk composition assay is essential for better applications in the dairy industry apart from processing and storage. Several techniques are reported in literature, but their applications are limited due to chemical entailment, invasive nature, and complicated procedures. The present work investigates the possibility of using milk foam properties as composition markers of milk. Surfactants play a key role in generating foams. In the present work, the effect of surfactants and temperature on foams produced from milk of different fat composition was investigated. Temperature effects and the impact of cationic, anionic, and non-ionic surfactants on foams produced from three milk types (cow milk, toned milk, and full cream milk) were studied. Toned milk added with an anionic surfactant sodium dodecyl sulphate (SDS) at 60 °C showed comparatively higher foamability of 122.4 mL. Among pure milk samples, toned milk showed a comparatively higher foamability of 114.65 mL. Cationic surfactant cetyltrimethylammonium bromide (CTAB) showed better milk foaming properties. Tween 80, a non-ionic surfactant showed a minimal or neutral effect on foam properties of milk. The results attained could lay the foundations for developing a novel milk assay protocol with the use of surfactant foams and thermal pre-treatments.

Reduced cytotoxicity of CTAB-templated silica layer on gold nanorod using fluorescence dyes and its application in cancer theranostics

Cytotoxicity of cetyltrimethylammonium bromide (CTAB)-templated silica-coated gold nanorod (CGNR@SiO2) was confirmed to be severe even after the washing process because of the residual CTAB surfactant. Calcination to eliminate the CTAB template induced dissolution of the gold nanorod (GNR) core and caused a blue-shift in the longitudinal surface plasmon resonance (LSPR) mode of the GNR from the near-infrared to visible wavelength. In contrast, the CTAB template was effectively removed from CGNR@SiO2 without interference of the plasmonic property of the core GNR by amine-functionalized fluorescence dyes such as methylene blue (MB) and rhodamine B (RB). The RB was more efficient in substituting the residual CTAB through electrostatic interactions than the MB. Moreover, the resulting products exhibited excellent surface-enhanced Raman scattering performance to detect a few cancer cells. The MB and RB molecules as visible light photosensitizer (PS) were activated by near-infrared (NIR) excitation light through transfer of the NIR-driven plasmonic hot electrons from the core GNR to the PS molecules. It is noteworthy that the RB-loaded CGNR@SiO2 exhibited excellent cancer cell killing efficiency via generation of abundant reactive oxygen species (ROS) under NIR laser irradiation, although the concentration of the intracellular GNR was too low to induce the photothermal effect.