Printable multi-marker biochips that enable simultaneous quantitative detection of multiple target

Printable multi-marker biochips that enable simultaneous quantitative detection of multiple target biomarkers in point-of-care and resource-limited settings are a holy grail in the field of biodiagnostics. approach. Furthermore plasmonic calligraphy also serves as a simple and efficient means to isolate multiple test domains on a single test strip which facilitates multiplexed biodetection and multi-marker biochips. Plasmonic calligraphy which can be potentially automated by implementing having a robotic arm serves as an alternate path ahead to conquer the limitations of standard ink-jet printing. Keywords: Localized surface plasmon resonance Calligraphy Platinum nanorods Plasmonic ink 1 Introduction Sele Owing to several advantages such as high specific surface area superb wicking properties compatibility with standard printing methods significant cost reduction and easy disposability paper substrates Nortadalafil are getting increased attention in biodiagnostics food quality screening environmental monitoring flexible energy and electronic devices (Chen et al. 2008 Cheng et al. 2010 Huang et al. 2013 Lee et al. 2010 2011 Li et al. 2010 2012 Martinez et al. 2007 2009 Nergiz et al. 2013 Parolo and Merkoci 2013 Tian et al. 2012 Recent surge in the activity related to paper-based diagnostic products is primarily focused on realizing microfluidic paper-based analytical products (μPADs) for point-of-care assays and inexpensive diagnostic tools for resource-limited environments (Lewis et al. 2012 Martinez et al. 2009 Most of these developments rely on labor- time- and/or resource-intensive patterning techniques such as photolithography wax printing ink-jet printing of polydimethylsiloxane (PDMS) to produce fluidic pathways and/or different practical areas for site-selective adsorption of the biochemical reagents (Abe et al. 2008 Bruzewicz et al. 2008 Carrilho et al. 2009 Martinez et al. 2007 Noh and Phillips 2010 Olkkonen et al. 2010 Osborn et al. 2010 Qu et al. 2012 Yu and White colored 2013 Moreover implementing ink-jet printing with biomolecules can result in loss of acknowledgement functionality due to the inherent temperature variations associated with ink-jet printing process. These Nortadalafil considerations clearly highlight the need for a simple and biofriendly technique that enables multi-marker biochips for point-of-care and resource-limited settings. The refractive index level of sensitivity of localized surface plasmon resonance (LSPR) of plasmonic nanostructures renders it a stylish transduction platform for chemical and biological sensing (Abbas et al. 2013 Anker et al. 2008 Englebienne 1998 Haes et al. 2005 Haes and Vehicle Duyne 2002 Kattumenu et al. 2011 Maier and Atwater 2005 Mayer and Hafner 2011 Riboh et al. 2003 Rosi and Mirkin 2005 Sepúlveda et al. 2009 Svedendahl et al. 2009 Yonzon et al. 2004 We have recently shown plasmonic paper comprised of biofunctionalized platinum nanorods (AuNRs) uniformly adsorbed in writing substrates (Tian et al. 2012 The bioplasmonic paper enabled the detection of aquaporin-1 a kidney malignancy biomarker in artificial urine down to a concentration of 10 ng/ml (Morrissey et al. 2010 Bioplasmonic paper fabricated by immersing a paper substrate into biofunctionalized AuNRs answer facilitates the detection of one specific target protein in the analyte answer (e.g. urine). Perceivably this immersion approach hinders spatial multiplexing (i.e. realizing multiple test domains for the detection of more than one target biomolecule on the same substrate) as it results in uniform adsorption of the Nortadalafil bioconjugated nanorods over the entire paper surface. Here we demonstrate a simple yet powerful plasmonic calligraphy approach for realizing multiplexed label-free bioassays using a regular ballpoint pen filled with platinum nanorods or biofunctionalized platinum nanorods as (bio)plasmonic ink. Plasmonic calligraphy gives two unique advantages over plasmonic paper substrates acquired by immersion method as reported previously. Firstly plasmonic calligraphy serves as a facile method to miniaturize the test website size to few mm2 which significantly improves the level of sensitivity of the plasmonic biosensor compared to.