%0 Journal Article
%T Multiplex Immunoassays of Plant Viruses Based on Functionalized Upconversion Nanoparticles Coupled with Immunomagnetic Separation
%A Mingzhe Zhang
%A Wujian Chen
%A Xi Chen
%A Yongjiang Zhang
%A Xiaojia Lin
%A Zhiyi Wu
%A Mingfu Li
%J Journal of Nanomaterials
%D 2013
%I Hindawi Publishing Corporation
%R 10.1155/2013/317437
%X A sensitive, specific and rapid method for the detection of three different kinds of plant viruses including tomato ringspot virus (ToRSV), bean pod mottle virus (BPMV) and arabis mosaic virus (ArMV) was demonstrated using novel upconversion nanoparticles (UCNPs) as a fluorescence marker coupled with immunomagnetic separation. Magnetic nanoparticles (MNPs, ~100£¿nm) were coated with different antibodies were employed to capture and enrich the target viruses. Then antibody-conjugated UCNPs as signal probes were added to form sandwich complexes. This was followed by a fluorescence measurement using a 980£¿nm laser. This method not only avoids the difficulty in simultaneous detection of multiple independent organic fluorphores that require distinct excitation wavelengths, and auto-fluorescence of biological samples due to the higher-energy excitation of QDs but also amplifies detection signal by UCNPs-tags together with easy separation of samples by magnetic forces, demonstrating the potential to be used for detecting virus in the field of environmental safety and other fields. 1. Introduction There is increasing interest in the development of nanotechnology for bioassay [1, 2]. In the past two decades, optical and magnetic materials have attracted much attention due to their importance in the fields of chemistry, biology, medical sciences, and biotechnology [3]. Fe3O4 nanoparticles are one of the most intensively studied magnetic nanoparticles and can be applied in a variety of areas, ranging from drug delivery [4] and biosensing [5], dynamic sealing [6], and cell labeling [7] to magnetic resonance imaging [8]. Moreover, MNPs are well suited for target capturing, enrichment, and isolation [9]. Accordingly, they can be used for isolating cells [10] and bacteria [11] and for removing environmental toxins such as heavy metals and chemical waste [12]. Research on fluorescent nanomaterials has also gained extensive attention in the past decade. Recently, colloidal semiconductor nanocrystals (quantum dots, QDs) have attracted many researchers due to their broad excitation, size-dependent photoluminescence with narrow emission bandwidth covering a wide spectral range, unusual photochemical stability, and relatively high photoluminescence quantum yield [13]. However, QDs excited by blue or short-wavelength UV radiation can induce autofluorescence of most biological tissues [14], which greatly decreases the sensitivity of detection. Moreover, the risk of systemic toxicity remains high, given their incorporation of heavy metals (e.g., Pb, Cd), precluding their
%U http://www.hindawi.com/journals/jnm/2013/317437/