Publications (42)263.79 Total impact

  • [Show abstract] [Hide abstract] ABSTRACT: Dengue virus (DENV) and West Nile virus (WNV) are two well-documented mosquito-borne flaviviruses that cause significant health problems worldwide. Driven by this need, we have developed a bioconjugated gold nanoparticle (AuNP) based surface enhanced Raman spectroscopy (SERS) probe for the detection of both DENV and WNV. Reported data demonstrate that the antiflavivirus 4G2 antibody conjugated gold nanoparticle (GNP) SERS probe can be used as a Raman fingerprint for the ultrasensitive detection of DENV and WNV selectively. Experimental data show that, due to the plasmon coupling in nanoassembly, antibody conjugated GNP based SERS is able to detect as low as 10 plaque-forming units (PFU)/mL of DENV-2 and WNV, which is comparable with the sensitivity of quantitative PCR based assays. Selectivity of our probe was validated using another mosquito-borne chikungunya virus (CHIKV) as a negative control. Experimental data demonstrate that the huge enhancement of SERS intensity is mainly due to strong electric field enhancement, which has been confirmed by a finite-difference time-domain (FDTD) simulation. Reported FDTD simulation data indicate the SERS enhancement factor can be more than 10,000 times, due to the assembled structure. Reported results suggest that bioconjugated AuNP-4G2 based SERS probes have great potential to be used to screen viral particles in clinical and research based laboratories.
    No preview · Article · Sep 2015 · The Journal of Physical Chemistry C
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    [Show abstract] [Hide abstract] ABSTRACT: Although prostate cancer has been known for thousands of years, it is a major public health issue for men even in the 21st century. As the understanding of cancer biology and the signaling pathways advances, it is now well understood that the detection of prostate cancer circulating tumor cells (CTCs) is an invaluable tool for monitoring the progression and finding possible therapies. Driven by this need, in this article, the development of magnetic-nanoparticle-attached theranostic graphene oxide (GO) is reported for targeted capture of prostate CTCs, accurate diagnosis, and combined therapeutic action of prostate cancer. Reported results show that anti-epithelial cell adhesion molecule (EpCAM) antibody and A9-aptamer-attached flower-shaped magnetic nanoparticle-bound 2D graphene can be used for selective capture and label-free multicolor luminescence imaging of LNCaP prostate cancer cell from infected blood. Experimental data demonstrate that indocyanine green (ICG)-bound A9-aptamer-attached theranostic GO is capable of external near IR 785 nm light-driven combined synergistic photothermal and photodynamic treatment of prostate cancer. Possible mechanisms for targeted capture, accurate analysis, and combined therapeutic actions have been discussed. Experimental results show that the theranostic GO can have enormous potential for real-life applications, once optimized properly in clinical settings.
    Full-text · Article · Dec 2014 · Particle and Particle Systems Characterization
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    [Show abstract] [Hide abstract] ABSTRACT: According to the World Health Organization, even in the 21st century, more than one million children die each year due to the rotavirus contamination of drinking water. Therefore, accurate identification and removal of rotavirus are very important to save childrens’ lives. Driven by the need, in this Letter, we report for the first time highly selective identification and removal of rotavirus from infected water using a bioconjugated hybrid graphene oxide based three-dimensional (3D) solid architecture. Experimental results show that due to the presence of a high intensity of “hot spots” in the 3D network, an antibody-attached 3D plasmonic–magnetic architecture can be used for accurate identification of rotavirus using surface-enhanced Raman spectroscopy (SERS). Reported data demonstrate that the antibody-attached 3D network binds strongly with rotavirus and is capable of highly efficient removal of rotavirus, which has been confirmed by SERS, fluorescence imaging, and enzyme-linked immunosorbent assay (ELISA) data. We discuss a possible mechanism for accurate identification and efficient removal of rotavirus from infected drinking water.
    Full-text · Article · Sep 2014 · Journal of Physical Chemistry Letters
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    [Show abstract] [Hide abstract] ABSTRACT: Multiple drug-resistance bacteria (MDRB) infection is one of the top three threats to human health according to the World Health Organization (WHO). Due to the large penetration depth and reduced photodamage, two-photon imaging is a highly promising technique for clinical MDRB diagnostics. Since most commercially available water-soluble organic dyes have low two-photon absorption cross-section and rapid photobleaching tendency, their applications in two-photon imaging is highly limited. Driven by the need, in this article we report extremely high two-photon absorption from aptamer conjugated graphene oxide (σ2PA = 50800 GM) which can be used for highly efficient two-photon fluorescent probe for MDRB imaging. Reported experimental data show that two-photon photoluminescence imaging color, as well as luminescence peak position can be tuned from deep blue to red, just by varying the excitation wavelength without changing its chemical composition and size. We have demonstrated that graphene oxide (GO) based two-photon fluorescence probe is capable of imaging of multiple antibiotics resistance MRSA in the first and second biological transparency windows using 760–1120 nm wavelength range.
    Full-text · Article · Aug 2014 · Scientific Reports
  • [Show abstract] [Hide abstract] ABSTRACT: Cancer is one of the life-threatening diseases which is rapidly becoming a global pandemic. Driven by the need, here we report for the first time aptamer conjugated theranostic magnetic hybrid graphene oxide based assay for highly sensitive tumor cell detection from blood sample with combined therapy capability. AGE-aptamer conjugated theranostic magnetic nanoparticle attached hybrid graphene oxide was developed for highly selective detection of tumor cells from infected blood sample. Experimental data indicate that hybrid graphene can be used as multi-color luminescence platform for selective imaging of G361 human malignant melanoma cancer cells. Reported results have also shown that indocyanine green (ICG) bound AGE-aptamer attached hybrid graphene oxide is capable of combined synergistic photothermal & photodynamic treatment of cancer. Targeted combined therapeutic treatment using 785 nm NIR light indicates that the multimodal therapeutic treatment is highly effective for malignant melanoma cancer therapy. Reported data show that aptamer conjugated theranostic graphene oxide based assay has exciting potential for improving cancer diagnosis and treatment.
    No preview · Article · Jul 2014 · Faraday Discussions
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    [Show abstract] [Hide abstract] ABSTRACT: Human cytomegalovirus (CMV) is a herpesvirus that causes major health problems in neonates as well as in immunocompromised individuals. At present, a vaccine is not available for CMV infection and the available antiviral drugs suffer from toxicity, poor efficacy and resistance. Here, we chemically conjugated a monoclonal antibody raised against CMV surface glycoprotein (gB) with gold nanoparticles (GNP) and characterized the potential of this gB-GNP conjugate for antiviral activity against CMV. The gB-GNP blocks viral replication, virus-induced cytopathogenic effects and virus spread in cell culture without inducing cytotoxicity. High concentrations of gB-GNP that coat the surface of virus particles block virus entry, whereas lower concentrations block a later stage of virus life cycle. Also, cells treated with gB-GNP gain resistance to CMV infection. In addition, infected cells when bound to gB-GNP can be selectively lysed after exposing them to specific wavelength of laser (nanophotothermolysis). Thus, we have not only designed a potential antiviral strategy that specifically blocks CMV infection at multiple stages of virus life cycle, but we have also characterized a technique that can potentially be useful in eliminating CMV infected cells from donor tissue during transplant or transfusion.
    Full-text · Article · Jul 2014 · Scientific Reports
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    [Show abstract] [Hide abstract] ABSTRACT: Cancer, a life-threatening disease, has become a global pandemic. Targeted tumor imaging using near-infrared (NIR) light is the key to improve the penetration depth and it is highly promising for clinical tumor diagnostics. Driven by this need, in this Letter we have reported aptamer conjugated graphene oxide-based two-photon imaging of breast tumor cells selectively. Reported data indicate that there is an extremely high two-photon absorption from aptamer conjugated graphene oxide (sigma(2PA) = 46890 GM). Experimental data show that two-photon luminescence signal remains almost unchanged even after 2 h of illuminations. Reported results show that S6 RNA aptamers conjugated graphene oxide-based two-photon fluorescence can be used for selective two-photon imaging of SK-BR-3 breast tumor cell in second biological transparency windows using 1100 nm wavelength. Experimental data demonstrate that it is highly capable of distinguishing targeted breast cancer SK-BR-3 cells from other nontargeted MDA-MB-231 breast cancer cells.
    Full-text · Article · Jun 2014 · Journal of Physical Chemistry Letters
  • [Show abstract] [Hide abstract] ABSTRACT: In the last few decades, Förster resonance energy transfer (FRET) based spectroscopy rulers have served as a key tool for the understanding of chemical and biochemical processes, even at the single molecule level. Since the FRET process originates from dipole-dipole interactions, the length scale of a FRET ruler is limited to a maximum of 10 nm. Recently, scientists have reported a nanomaterial based long-range optical ruler, where one can overcome the FRET optical ruler distance dependence limit, and which can be very useful for monitoring biological processes that occur across a greater distance than the 10 nm scale. Advancement of nanoscopic long range optical rulers in the last ten years indicate that, in addition to their long-range capability, their brightness, long lifetime, lack of blinking, and chemical stability make nanoparticle based rulers a good choice for long range optical probes. The current review discusses the basic concepts and unique light-focusing properties of plasmonic nanoparticles which are useful in the development of long range one dimensional to three dimensional optical rulers. In addition, to provide the readers with an overview of the exciting opportunities within this field, this review discusses the applications of long range rulers for monitoring biological and chemical processes. At the end, we conclude by speculating on the role of long range optical rulers in future scientific research and discuss possible problems, outlooks and future needs in the use of optical rulers for technological applications.
    No preview · Article · Jun 2014 · Chemical Society Reviews
  • [Show abstract] [Hide abstract] ABSTRACT: Trace level identification of explosive molecules are very important not only for security screening but also for the environment and human health. Driven by the need, the current article reports for the first time gold nanocage–graphene oxide hybrid platform for the spectral fingerprint and the trace level identification of RDX and TNT. Reported experimental data using RDX show that the surface-enhanced Raman spectroscopy (SERS) enhancement factor for graphene oxide (GO) attached gold nanocage assembly is 4 orders of magnitude higher than only nanocage, and it is due to the enormous field enhancement for the nanocage assembly. The current article demonstrates that label-free nitro-explosive identification limits using hybrid platform can be as low as 10 fM for TNT and 500 fM for RDX, which indicate that gold nanocage–graphene oxide assembly can be very attractive for a variety of practical applications.
    No preview · Article · Mar 2014 · The Journal of Physical Chemistry C
  • [Show abstract] [Hide abstract] ABSTRACT: This communication reports for the first time the development of multifunctional graphene oxide for the ultra-sensitive and label-free detection of malignant melanoma from an infected blood sample.
    No preview · Article · Mar 2014
  • [Show abstract] [Hide abstract] ABSTRACT: Paresh C. Ray and co-workers report on page 357 the development of multifunctional theranostic nanoplatforms, which is capable of targeted detection and destruction of methicillin-resistant Staphylococcus aureus (MRSA) from whole blood. The image shows that the theranostic nanoplatform has a great potential for simultaneous separation, imaging and multimodal photodestruction of MRSA in the blood sample.
    No preview · Article · Mar 2014 · Particle and Particle Systems Characterization
  • [Show abstract] [Hide abstract] ABSTRACT: Bloodstream infection with methicillin-resistant Staphylococcus aureus (MRSA) and other drug-resistant bacteria kill several million people in the world every year. Detection of drug-resistant bacteria in the blood stream is clinically important to save lives. Driven by this need, multifunctional theranostic nanoplatforms have been developed for simultaneous targeted imaging and multimodal photodestruction of MRSA in a whole-blood sample. Experimental data for the whole-blood sample spiked with MRSA show that the theranostic nanoplatform can be used for fluorescence imaging after magnetic separation even in a 10−5:1 ratio. A targeted photodynamic and photothermal combined treatment shows that the multimodal treatment regime can dramatically enhance the possibility of destroying MRSA in vitro. Therefore, our developed theranostic nanoplatform have a great potential as a fluorescent marker and as a light absorber for combined therapy in clinical settings. The possible mechanisms and operating principles are discussed for targeted imaging and combined therapeutic actions using theranostic nanoplatform.
    No preview · Article · Mar 2014 · Particle and Particle Systems Characterization
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    Zhen Fan · Peter P Fu · Hongtao Yu · Paresh C Ray
    [Show abstract] [Hide abstract] ABSTRACT: Cancer is the second leading cause of death in the USA according to the American Cancer Society. In the past 5 years, "theranostic nanomedicine", for both therapeutics and imaging, has shown to be "the right drug for the right patient at the right moment" to manage deadly cancers. This review article presents an overview of recent developments, mainly from the authors' laboratories, along with potential medical applications for theranostic nanomedicine including basic concepts and critical properties. Finally, we outline the future research direction and possible challenges for theranostic nanomedicine research.
    Preview · Article · Mar 2014 · Journal of Food and Drug Analysis
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    [Show abstract] [Hide abstract] ABSTRACT: For several decades, cancer is one of the most life-threatening diseases. For enhancing anticancer efficiency with minimum side effects, combination therapy is envisioned. Current manuscript reports the development of methylene blue (MB) bound nanoplatform, which is capable of delivering targeted diagnostic and combined synergistic photothermal & photodynamic treatment of cancer. Experimental data found that, once nanoparticle binds with the target cell surface, it can detect LNCaP human prostate can cell selectively using fluorescence imaging. Our result shows that the therapeutic actions can be controlled with external NIR light. No cytotoxicity was observed in the absence of NIR light. Targeted photodynamic & photothermal treatment using 785 nm NIR light, show that the multimodal treatment regime can dramatically enhance the possibility of destroying LNCaP prostate cancer cells in vitro. We discussed the possible mechanisms and operating principle for the targeted imaging and combined therapeutic actions. Our experimental data show that our nanoplatform has a great potential for cancer imaging & NIR light activated combined therapy in clinical settings.
    Preview · Article · Feb 2014 · Molecular Pharmaceutics
  • [Show abstract] [Hide abstract] ABSTRACT: Second harmonic generation (SHG) imaging using near infrared laser light is the key to improving penetration depths, leading to biological understanding. Unfortunately, currently SHG imaging techniques have limited capability due to the poor signal-to-noise ratio, resulting from the low SHG efficiency of available dyes. Targeted tumor imaging over nontargeted tissues is also a challenge that needs to be overcome. Driven by this need, in this study, the development of two-photon SHG imaging of live cancer cell lines selectively by enhancement of the nonlinear optical response of gold nanocage assemblies is reported. Experimental results show that two-photon scattering intensity can be increased by few orders of magnitude by just developing nanoparticle self-assembly. Theoretical modeling indicates that the field enhancement values for the nanocage assemblies can explain, in part, the enhanced nonlinear optical properties. Our experimental data also show that A9 RNA aptamer conjugated gold nanocage assemblies can be used for targeted SHG imaging of the LNCaP prostate cancer cell line. Experimental results with the HaCaT normal skin cell lines show that bioconjugated nanocage-based assemblies demonstrate SHG imaging that is highly selective and will be able to distinguish targeted cancer cell lines from other nontargeted cell types. After optimization, this reported SHG imaging assay could have considerable application for biology.
    No preview · Article · Jan 2014 · Chemistry - A European Journal
  • No preview · Chapter · Jan 2014
  • [Show abstract] [Hide abstract] ABSTRACT: The emergence of multidrug-resistant-bacteria (MDRB) infection poses a major burden to modern healthcare. Early detection in the bloodstream and a new strategy development for MDRB infection treatment without antibiotics are clinically significant to save millions of lives every year. To tackle the MDRB challenge, the current manuscript reports the design of “multifunctional nanoplatforms” consisting of a magnetic core–plasmonic shell nanoparticle, a methylene blue-bound aptamer, and an MDRB Salmonella DT104 specific antibody. The reported “multifunctional nanoplatform” is capable of targeted separation from a blood sample and sensing and multimodal therapeutic killing of MDRB. Experimental data using an MDRB-infected whole-blood sample show that nanoplatforms can be used for selective magnetic separation and fluorescence imaging. In vitro light-triggered photodestruction of MDRB, using combined photodynamic and photothermal treatment, shows that the multimodal treatment regime can enhance MDRB killing significantly. We discussed the possible mechanisms on combined synergistic therapy for killing MDRB. The “multifunctional nanoplatform” reported in this manuscript has great potential for the imaging and combined therapy of MDRB in clinical settings.
    No preview · Article · Oct 2013 · ACS Applied Materials & Interfaces
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    [Show abstract] [Hide abstract] ABSTRACT: A metal nanoparticle attached to graphene oxide has the ability to open a new avenue of research with significant opportunities in the biomedical field. In this Letter, we report graphene oxide attached to a popcorn-shaped gold nanoparticle based hybrid SERS probe with ultrasensitive label-free sensing of HIV DNA and bacteria and provide its chemical fingerprint. Our SERS data with the hybrid material shows that it can be used for label-free detection of HIV DNA on the femto-molar level without any labeling. Experimental data with a novel SERS substrate show excellent reproducibility of the SERS signal. The current Letter demonstrates that the label-free SERS detection limit using a hybrid material can be as low as 10 CFU/mL for MRSA bacteria. The possible mechanism for very high sensitivity has been discussed.
    Full-text · Article · Oct 2013 · Journal of Physical Chemistry Letters
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    [Show abstract] [Hide abstract] ABSTRACT: Over the last few years, one of the most important and complex problems facing our society is treating infectious diseases caused by multidrug-resistant bacteria (MDRB), by using current market-existing antibiotics. Driven by this need, we report for the first time the development of the multifunctional popcorn-shaped iron magnetic core-gold plasmonic shell nanotechnology-driven approach for targeted magnetic separation and enrichment, label-free surface-enhanced Raman spectroscopy (SERS) detection, and the selective photothermal destruction of MDR Salmonella DT104. Due to the presence of the "lightning-rod effect", the core-shell popcorn-shaped gold-nanoparticle tips provided a huge field of SERS enhancement. The experimental data show that the M3038 antibody-conjugated nanoparticles can be used for targeted separation and SERS imaging of MDR Salmonella DT104. A targeted photothermal-lysis experiment, by using 670 nm light at 1.5 W cm(-2) for 10 min, results in selective and irreparable cellular-damage to MDR Salmonella. We discuss the possible mechanism and operating principle for the targeted separation, label-free SERS imaging, and photothermal destruction of MDRB by using the popcorn-shaped magnetic/plasmonic nanotechnology.
    Full-text · Article · Feb 2013 · Chemistry - A European Journal
  • [Show abstract] [Hide abstract] ABSTRACT: Recent advances in nanotechnology have attracted a great deal of public interest because of the need for and applications of nanomaterials in many areas of human endeavor. Nanotechnology is now rapidly evolving from the discovery phase to the application phase, and therefore nanomaterials in consumer products will be exposed to environmental media as we move forward. The need to evaluate nanotoxicity is becoming increasingly important day by day. This review presents a summary of recent in vivo and in vitro research efforts toward understanding the fate, behavior, and toxicity of various classes of nanomaterials. The possible challenges and future requirements for making nanotechnology safe for the environment are discussed.
    No preview · Chapter · Jan 2013