Due to the abundance of silica and carbon in rice (Oryza sativa) husk (RH), we exploited it for t... more Due to the abundance of silica and carbon in rice (Oryza sativa) husk (RH), we exploited it for the synthesis of a mesoporous silica oxide micro-particles (meso-SiO 2 )/C-dot complex for biological imaging using a novel hot injection method commonly used for semiconductor quantum dots. Carbon dots (C-dots) with a high degree of green fluorescence were observed under UV-light they were found to be embedded to a significant extent in meso-SiO 2 as confirmed by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The mesoporous nature of the complex was confirmed using N 2 adsorption-desorption measurements. Surface functionalization was studied using Fourier transform infrared spectroscopy (FTIR). The synthesized meso-SiO 2 /C-dots complex was used for labeling yeast cells since the fungi closely represents eukaryotic organisms. Furthermore, the meso-SiO 2 /C-dot complex was found to be highly bio-compatible for Vero cells. This study might help in the further utilization of the complex for the theranostic application of simultaneous cellular imaging and drug delivery.
The use of phenylalanine derived non-toxic carbon dots (C-dots) as a vehicle for the delivery of ... more The use of phenylalanine derived non-toxic carbon dots (C-dots) as a vehicle for the delivery of widely used anti-psychotic drug haloperidol (HaLO) is described in the present research work. The C-dots were found to have remarkable optical properties and to exhibit bright green fluorescence under UV light (l ex ¼ 365 nm). The UV-Vis spectrum of the C-dots exhibits peaks at 232 and 276 nm confirming their synthesis in solution.
We are reporting novel protocol for the synthesis of Carbon dots (C-dots) at 28±2 ºC using Sugar ... more We are reporting novel protocol for the synthesis of Carbon dots (C-dots) at 28±2 ºC using Sugar cane juice without any additive. To separate C-dots from other carbonaceous materials, we exploited Sucrose Density Gradient Centrifugation (SDGC). Discrete fractions obtained were studied for the presence of C-dots using UV-Vis spectroscopy, Field Emission Scanning Electron Microscopy (FE-SEM), High Resolution Transmission Electron Microscopy (HRTEM), X-Ray diffraction (XRD) and Raman Spectroscopy.
Use of Cysteamine hydrochloride (CHC) protected Gold nanorods (GNRs) as efficient carrier of wide... more Use of Cysteamine hydrochloride (CHC) protected Gold nanorods (GNRs) as efficient carrier of widely used anti-cancer drug doxorubicin using folic acid as navigational molecule is presented in this work. GNRs were found to have excellent drug loading capacity of >97%. A detailed comprehension of in-vitro drug release profile under ideal physiological condition was found to obey 1st order kinetics at pH 6.8, 5.3 and 7.2, an ideal milieu for drug delivery to solid tumours.
Impact of pH on the morphology of the Gold Nanoparticles (GNPs) synthesized using leaf extracts o... more Impact of pH on the morphology of the Gold Nanoparticles (GNPs) synthesized using leaf extracts of Azadirachta indica is reported here. pH of the plant extract significantly affected the morphology of the GNPs. At pH 2 along with the formation of spherical GNPs, initiation of the non-spherical morphology also occurred. The non-spherical GNPs developed into more distinct gold nano-cubes when the pH of the plant extract was adjusted to pH 4. At pH 6, the optical as well as morphological features of the triangles, hexagons and plates became more conspicuous. It must be mentioned here that there were presence of some spherical GNPs also in each case that could have been an initiator of different morphologies directed by the pH of the reaction mixture. Presence of the dual absorption maxima confirmed the formation of non-spherical GNPs. Formation of spherical as well as non spherical nanoparticles such as gold nano-prisms and nano-hexagons was observed at pH 8. To confirm the possible involvement of nitrate reductase; its activity as a catalyst and /or template to navigate the formation of anisotropic GNPs is also depicted. It was found that the activity of the NR was drastically reduced after the formation of GNPs.
Azadirachta indica as a biological sink for fabrication of Gold nanoparticles (GNPs) and its appl... more Azadirachta indica as a biological sink for fabrication of Gold nanoparticles (GNPs) and its applications in efficient delivery of doxorubicin (DOX) is presented here. Sucrose density gradient centrifugation was used to isolate the spherical GNPs of <50nm from the mixture (containing both spherical and non-spherical) of nanoparticles synthesized using leaf of A. indica at inherent pH (6.14). The stability of GNPs due to the biological capping agents was scrutinised by measuring the flocculation parameter which was found to be in the range of 0-0.65. On the surface of these capped GNPs; doxorubicin was attached along with activated Folic acid (FA) as navigational molecules for the targeted drug delivery. Attachments were verified using FTIR which confirmed the formation of non-covalent interactions. The GNPs-FA-DOX complex was found be non-toxic for normal cells and considerably toxic for HeLa cells. The drug loading capacity of the GNPs was found to 93%. Doxorubicin release kinetics using GNPs followed 1st order at pH 5.3 which is ideal for solid tumor targeting.
This research account is an attempt to apprehend the important parameters for synthesizing monodi... more This research account is an attempt to apprehend the important parameters for synthesizing monodispersed Gold nano rods (GNR) of desired aspect ratios. There is plethora of synthetic strategies for the synthesis of GNR amongst which seed-mediated one is the most celebrated one since it is simpler and is capable of synthesizing GNR of desired aspect ratio. But the biggest hurdle is to standardize all the parameters such as concentration of gold chloride, CTAB, AgNO3 and pH for GNR synthesis and also comprehend the most accentuating and key parameters which affects the most. This is possible only with the help of a Taguchi L9 Orthogonal array design which is a statistical tool to optimize the parameters and also find the percentage effect of each parameter. The S/N ratio which was selected for the synthesis of desired aspect ratio was 'smaller the better' which could assist in the synthesis of GNRs of desired aspect ratios. After optimization the most influential parameters for GNR synthesis is found to be 0.5mM Gold, 0.2M CTAB, 5mM Silver nitrate and 3.1 pH.
In this paper biosynthesis of stable gold nanoparticles (GNPs) using Pseudomonas denitrificans ex... more In this paper biosynthesis of stable gold nanoparticles (GNPs) using Pseudomonas denitrificans exudates is demonstrated. Acidic pH (3.0) and microbial incubation temperature of P. denitrificans was found to induce biosynthesis of GNP in 100 ppm aqueous solution of aurochlorate salt. The optical properties and morphology were verified using UV-Vis spectroscopy and High Resolution Transmission electron microscopy. HRTEM micrographs as well as the SPR peaks of UV-Vis spectra showed that the size of the GNPs ranged from 25-30 nm. . The crystalline nature of gold nanoparticles was examined using XRD and was found to be face centered cubic. FTIR analyses of such GNPs possess sulphydryl, amido, carbonyl functional groups which depicts the presence of peptides involved in capping the nanoparticle leading to its stability. Moreover, the stability of GNPs synthesized from Pseudomonas denitrificans exudates was compared with chemically synthesized GNPs with the help of 5M NaCl. An analysis of nitrate reductase activity in microbial exudates exhibited its involvement in the synthesis of GNPs.
Due to the abundance of silica and carbon in rice (Oryza sativa) husk (RH), we exploited it for t... more Due to the abundance of silica and carbon in rice (Oryza sativa) husk (RH), we exploited it for the synthesis of a mesoporous silica oxide micro-particles (meso-SiO 2 )/C-dot complex for biological imaging using a novel hot injection method commonly used for semiconductor quantum dots. Carbon dots (C-dots) with a high degree of green fluorescence were observed under UV-light they were found to be embedded to a significant extent in meso-SiO 2 as confirmed by transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The mesoporous nature of the complex was confirmed using N 2 adsorption-desorption measurements. Surface functionalization was studied using Fourier transform infrared spectroscopy (FTIR). The synthesized meso-SiO 2 /C-dots complex was used for labeling yeast cells since the fungi closely represents eukaryotic organisms. Furthermore, the meso-SiO 2 /C-dot complex was found to be highly bio-compatible for Vero cells. This study might help in the further utilization of the complex for the theranostic application of simultaneous cellular imaging and drug delivery.
The use of phenylalanine derived non-toxic carbon dots (C-dots) as a vehicle for the delivery of ... more The use of phenylalanine derived non-toxic carbon dots (C-dots) as a vehicle for the delivery of widely used anti-psychotic drug haloperidol (HaLO) is described in the present research work. The C-dots were found to have remarkable optical properties and to exhibit bright green fluorescence under UV light (l ex ¼ 365 nm). The UV-Vis spectrum of the C-dots exhibits peaks at 232 and 276 nm confirming their synthesis in solution.
We are reporting novel protocol for the synthesis of Carbon dots (C-dots) at 28±2 ºC using Sugar ... more We are reporting novel protocol for the synthesis of Carbon dots (C-dots) at 28±2 ºC using Sugar cane juice without any additive. To separate C-dots from other carbonaceous materials, we exploited Sucrose Density Gradient Centrifugation (SDGC). Discrete fractions obtained were studied for the presence of C-dots using UV-Vis spectroscopy, Field Emission Scanning Electron Microscopy (FE-SEM), High Resolution Transmission Electron Microscopy (HRTEM), X-Ray diffraction (XRD) and Raman Spectroscopy.
Use of Cysteamine hydrochloride (CHC) protected Gold nanorods (GNRs) as efficient carrier of wide... more Use of Cysteamine hydrochloride (CHC) protected Gold nanorods (GNRs) as efficient carrier of widely used anti-cancer drug doxorubicin using folic acid as navigational molecule is presented in this work. GNRs were found to have excellent drug loading capacity of >97%. A detailed comprehension of in-vitro drug release profile under ideal physiological condition was found to obey 1st order kinetics at pH 6.8, 5.3 and 7.2, an ideal milieu for drug delivery to solid tumours.
Impact of pH on the morphology of the Gold Nanoparticles (GNPs) synthesized using leaf extracts o... more Impact of pH on the morphology of the Gold Nanoparticles (GNPs) synthesized using leaf extracts of Azadirachta indica is reported here. pH of the plant extract significantly affected the morphology of the GNPs. At pH 2 along with the formation of spherical GNPs, initiation of the non-spherical morphology also occurred. The non-spherical GNPs developed into more distinct gold nano-cubes when the pH of the plant extract was adjusted to pH 4. At pH 6, the optical as well as morphological features of the triangles, hexagons and plates became more conspicuous. It must be mentioned here that there were presence of some spherical GNPs also in each case that could have been an initiator of different morphologies directed by the pH of the reaction mixture. Presence of the dual absorption maxima confirmed the formation of non-spherical GNPs. Formation of spherical as well as non spherical nanoparticles such as gold nano-prisms and nano-hexagons was observed at pH 8. To confirm the possible involvement of nitrate reductase; its activity as a catalyst and /or template to navigate the formation of anisotropic GNPs is also depicted. It was found that the activity of the NR was drastically reduced after the formation of GNPs.
Azadirachta indica as a biological sink for fabrication of Gold nanoparticles (GNPs) and its appl... more Azadirachta indica as a biological sink for fabrication of Gold nanoparticles (GNPs) and its applications in efficient delivery of doxorubicin (DOX) is presented here. Sucrose density gradient centrifugation was used to isolate the spherical GNPs of <50nm from the mixture (containing both spherical and non-spherical) of nanoparticles synthesized using leaf of A. indica at inherent pH (6.14). The stability of GNPs due to the biological capping agents was scrutinised by measuring the flocculation parameter which was found to be in the range of 0-0.65. On the surface of these capped GNPs; doxorubicin was attached along with activated Folic acid (FA) as navigational molecules for the targeted drug delivery. Attachments were verified using FTIR which confirmed the formation of non-covalent interactions. The GNPs-FA-DOX complex was found be non-toxic for normal cells and considerably toxic for HeLa cells. The drug loading capacity of the GNPs was found to 93%. Doxorubicin release kinetics using GNPs followed 1st order at pH 5.3 which is ideal for solid tumor targeting.
This research account is an attempt to apprehend the important parameters for synthesizing monodi... more This research account is an attempt to apprehend the important parameters for synthesizing monodispersed Gold nano rods (GNR) of desired aspect ratios. There is plethora of synthetic strategies for the synthesis of GNR amongst which seed-mediated one is the most celebrated one since it is simpler and is capable of synthesizing GNR of desired aspect ratio. But the biggest hurdle is to standardize all the parameters such as concentration of gold chloride, CTAB, AgNO3 and pH for GNR synthesis and also comprehend the most accentuating and key parameters which affects the most. This is possible only with the help of a Taguchi L9 Orthogonal array design which is a statistical tool to optimize the parameters and also find the percentage effect of each parameter. The S/N ratio which was selected for the synthesis of desired aspect ratio was 'smaller the better' which could assist in the synthesis of GNRs of desired aspect ratios. After optimization the most influential parameters for GNR synthesis is found to be 0.5mM Gold, 0.2M CTAB, 5mM Silver nitrate and 3.1 pH.
In this paper biosynthesis of stable gold nanoparticles (GNPs) using Pseudomonas denitrificans ex... more In this paper biosynthesis of stable gold nanoparticles (GNPs) using Pseudomonas denitrificans exudates is demonstrated. Acidic pH (3.0) and microbial incubation temperature of P. denitrificans was found to induce biosynthesis of GNP in 100 ppm aqueous solution of aurochlorate salt. The optical properties and morphology were verified using UV-Vis spectroscopy and High Resolution Transmission electron microscopy. HRTEM micrographs as well as the SPR peaks of UV-Vis spectra showed that the size of the GNPs ranged from 25-30 nm. . The crystalline nature of gold nanoparticles was examined using XRD and was found to be face centered cubic. FTIR analyses of such GNPs possess sulphydryl, amido, carbonyl functional groups which depicts the presence of peptides involved in capping the nanoparticle leading to its stability. Moreover, the stability of GNPs synthesized from Pseudomonas denitrificans exudates was compared with chemically synthesized GNPs with the help of 5M NaCl. An analysis of nitrate reductase activity in microbial exudates exhibited its involvement in the synthesis of GNPs.
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