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.

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.

There is an increasing interest in rare earth (RE) doped nanoparticles (NPs) due to their sharp absorption and photoluminescence (PL) in the near infrared (NIR) spectral region. These NIR based nanoparticles (NPs) could allow biological imaging at substantial depths with enhanced contrast and high spatial resolution due to the absence of auto fluorescence in biological samples under infrared excitation. Here, we present the highly efficient infrared photoluminescence in GdF3:Nd3+ nanoparticles under 800 nm excitation within the hydrodynamic size limitations for bio-applications. The downconversion (Stokes emission) absolute quantum yield (QY) measurements in powder, poly maleic anhydride- alt-1- octadicene (PMAO) coated powder and colloidal solutions have been investigated. QY measurements have revealed that downconversion(Stokes emission)QY in an average 5 ± 2 nm sized GdF3: 1% Nd3+colloidalNPs are 2000 times higher than efficient upconversion (UC) particles NaYF4: 20 % Er/ 2% Yb of same size. Furthermore, the utility of these NIR emitting nanoparticles forbioimagingprobe has been demonstrated by confocal imaging and spectroscopic study.

Here we report the synthesis, characterization and application of a multifunctional surface functionalized GdF3:Nd3+ nanophosphor that exhibits efficient near infrared (NIR) fluorescence as well as magnetic properties, which can be utilized for bimodal imaging in medical applications. The nanoparticles are small with an average size of 5 nm and form stable colloids that last for several weeks without settling, enabling the use for several biomedical and photonic applications. Their excellent NIR properties, such as nearly 11 % quantum yield of the 1064 nm emission, make them ideal contrast agents and biomarkers for in vitro and in vivo NIR optical bioimaging. The nanophosphors which were coated with poly(maleic anhydride- alt-1-octadicene) (PMAO) were implemented in cellular imaging and show no significant cellular toxicity for concentrations up to 200 μg ml−1. Furthermore, the incorporation of Gd into the nanocrystalline structure supplies exceptional magnetic properties, making them ideal for use as magnetic resonance imaging (MRI) contrast agents. The utility of these NIR emitting nanoparticles in infrared bioimaging and as contrast agent in magnetic resonance imaging was demonstrated by confocal imaging, magnetic resonance and tissue experiments.

Optical properties of bovine ocular tissues were determined at laser wavelengths in the visible region. The inverse adding doubling (IAD), Kubelka–Munk (KM), and inverse Monte Carlo (IMC) methods were applied to the measured values of the total diffuse transmission, total diffuse reflection, and collimated transmission to determine the optical absorption and scattering coefficients of the bovine cornea, lens and retina at 457.9 nm, 488 nm, and 514.5 nm laser lines from an argon ion laser. The optical properties obtained from these three methods were compared, and their validity is discussed.