title: Coffee ring aptasensor for rapid protein detection.
abstract: We introduce a new biosensing platform for rapid protein detection that combines one of the simplest methods for biomolecular concentration, coffee ring formation, with a sensitive aptamer-based optical detection scheme. In this approach, aptamer beacons are utilized for signal transduction where a fluorescence signal is emitted in the presence of the target molecule. Signal amplification is achieved by concentrating aptamer-target complexes within liquid droplets, resulting in the formation of coffee ring "spots". Surfaces with various chemical coatings were utilized to investigate the correlation among surface hydrophobicity, concentration efficiency, and signal amplification. On the basis of our results, we found that the increase in the coffee ring diameter with larger droplet volumes is independent of surface hydrophobicity. Furthermore, we show that highly hydrophobic surfaces produce enhanced particle concentration via coffee ring formation, resulting in signal intensities 6-fold greater than those on hydrophilic surfaces. To validate this biosensing platform for the detection of clinical samples, we detected α-thrombin in human serum and 4-fold-diluted whole blood. Coffee ring spots from serum and blood produced detection signals up to 40 times larger than those from samples in liquid droplets. Additionally, this biosensor exhibits a lower limit of detection of 2 ng/mL (54 pM) in serum, and 4 ng/mL (105 pM) in blood. On the basis of its simplicity and high performance, this platform demonstrates immense potential as an inexpensive diagnostic tool for the detection of disease biomarkers, particularly for use in developing countries that lack the resources and facilities required for conventional biodetection practices.
authors.affiliation: Department of Bioengineering, University of California, Riverside, California 92521, United States.
authors.forename: Jessica T
authors.initials: JT
authors.lastname: Wen
authors.forename: Chih-Ming
authors.initials: CM
authors.lastname: Ho
authors.forename: Peter B
authors.initials: PB
authors.lastname: Lillehoj
mesh_terms: D052157:Aptamers, Nucleotide / Q000138:chemical synthesis*; D015374:Biosensing Techniques / Q000295:instrumentation / Q000379:methods*; D002232:Carbocyanines / Q000737:chemistry; D003102:Colloids; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D057927:Hydrophobic and Hydrophilic Interactions; D057230:Limit of Detection; D008856:Microscopy, Fluorescence; D011137:Polystyrenes / Q000737:chemistry*; D013696:Temperature; D013917:Thrombin / Q000032:analysis*
chemical_list: C569686:Alexa Fluor 647; D052157:Aptamers, Nucleotide; D002232:Carbocyanines; D003102:Colloids; D005456:Fluorescent Dyes; D011137:Polystyrenes; D013917:Thrombin
references.citation: Nat Struct Mol Biol. 2005 Oct;12(10):847-54
references.pmid: 16142245
references.citation: Anal Chem. 2009 Oct 1;81(19):8256-9
references.pmid: 19737006
references.citation: Biosens Bioelectron. 2005 Apr 15;20(10):2168-72
references.pmid: 15741093
references.citation: Anal Chem. 2011 Mar 15;83(6):1871-3
references.pmid: 21288015
references.citation: Angew Chem Int Ed Engl. 2012 Mar 12;51(11):2546-8
references.pmid: 22278914
references.citation: PLoS One. 2010 Aug 04;5(8):e11890
references.pmid: 20694194
references.citation: Anal Chem. 2011 Jun 1;83(11):4004-11
references.pmid: 21517100
references.citation: Anal Biochem. 2001 Jul 15;294(2):126-31
references.pmid: 11444807
references.citation: Anal Chem. 2009 Jan 1;81(1):87-93
references.pmid: 19117446
references.citation: Biosens Bioelectron. 2005 Dec 15;21(6):863-70
references.pmid: 16257654
references.citation: Chembiochem. 2005 Dec;6(12):2163-6
references.pmid: 16254932
references.citation: Biomol Eng. 2007 Oct;24(4):381-403
references.pmid: 17627883
references.citation: Anal Chem. 2007 Jul 1;79(13):5087-92
references.pmid: 17523596
references.citation: Anal Chem. 2009 Aug 15;81(16):6604-11
references.pmid: 20337374
references.citation: Biotechnol Bioeng. 2009 Aug 15;103(6):1049-59
references.pmid: 19431189
references.citation: Annu Rev Anal Chem (Palo Alto Calif). 2009;2:241-64
references.pmid: 20636061
references.citation: Nat Rev Microbiol. 2004 Mar;2(3):231-40
references.pmid: 15083158
references.citation: Biosens Bioelectron. 2009 Jul 15;24(11):3175-82
references.pmid: 19117748
references.citation: J Am Chem Soc. 2008 Feb 27;130(8):2380-1
references.pmid: 18247609
references.citation: Nano Lett. 2008 Dec;8(12):4386-90
references.pmid: 19367849
references.citation: Anal Chem. 2008 Jul 1;80(13):5110-7
references.pmid: 18522435
references.citation: Annu Rev Biomed Eng. 2008;10:107-44
references.pmid: 18358075
references.citation: Anal Chem. 2006 Jul 1;78(13):4727-31
references.pmid: 16808489
references.citation: Langmuir. 2010 Jul 20;26(14):11690-8
references.pmid: 20527912
references.citation: J Am Chem Soc. 2003 Jan 8;125(1):42-3
references.pmid: 12515502
references.citation: Biosens Bioelectron. 2009 Jul 15;24(11):3288-92
references.pmid: 19442509
references.citation: Clin Chem. 1999 Sep;45(9):1628-50
references.pmid: 10471678
references.citation: J Am Chem Soc. 2004 Sep 29;126(38):11768-9
references.pmid: 15382892
references.citation: Nat Biotechnol. 2006 Aug;24(8):971-83
references.pmid: 16900146
references.citation: J Phys Chem B. 2010 Apr 29;114(16):5269-74
references.pmid: 20353247
references.citation: Anal Chem. 2011 Sep 1;83(17):6641-7
references.pmid: 21774454
references.citation: Chem Commun (Camb). 2010 Aug 14;46(30):5563-5
references.pmid: 20532276
references.citation: J Am Chem Soc. 2006 Jan 25;128(3):780-90
references.pmid: 16417367
references.citation: Biochem Biophys Res Commun. 2007 Jan 19;352(3):812-7
references.pmid: 17150180
references.citation: Chem Commun (Camb). 2007 Jan 7;(1):73-5
references.pmid: 17279265
references.citation: Anal Chem. 2007 Apr 1;79(7):3016-9
references.pmid: 17338547
references.citation: Angew Chem Int Ed Engl. 2008;47(50):9685-90
references.pmid: 19003839