LETTERS NATURE NANOTECHNOLOGY DOL: 10.1038/NNANO. 2009.353 a1020 b105 PSA/CA153 spiked blood o PSA/CA153 spiked blood 1.015 CA15.3 -25 me(s) Time(s) +2.0 ng ml-I 15U ml-1C 1.000 Slope ratio=1.38 sAratiA-1 -250 Time(s) Figure 4 I Label-free sensing. All sensing measurements were performed at Vps=1V and VG=-5V and all sample introductions occurred at t=o Normalizations were performed by dividing device currents by the pre-addition(t <O)current level average. Vos drain-source voltage. a, Response of an anti-PSA functionalized sensor to a MPC purified blood sample initially containing 2.5 ng ml-I PSA(and also 30 U ml-l CA153), or a control sample containing neither. b, Response of an anti-CA15 functionalized sensor to a MPC-purified blood sample initially containing 30 U ml-CA153(and also 2.5 ng ml- PSA), or a control sample containing neither. c, d, Normalized response of two anti-PSA(c)and two anti-CA153(d) functionalized devices to MPC-purified blood containing both PSA and CA153, with concentrations labelled. A least-squares fit is represented by a solid black line over the selected endpoints). The ratio of the normalized slopes calibrates the ratio of concentrations. ansistor sensors Nano af the Debye screening length on nanowire field effect 29. Cantor, C.R. Schimmel, P. R. Biophysical Chemistry: Part l: The Behavior of t.7,3405-3409(2007) Biological Macromolecules( Freeman, 1980). 17. Zhou, H Ranish, J. A, Watts, J. D. Aebersold, R. Quantitative proteome 30. Homola. ]. Present and future of surface plasmon resonance biosensors. Anal Bioanal. Chen. 377, 528-539(2003). Biotechnol20,512-515(2002) 中 Comb. Chem. High Thc knows wogeieto thank L Strict for many helpful discussions.m. look 19. Hermanson, G. T. Bioconjugate Techniques(Elsevier, 1996). J. Bertram for blood samples, M. Power for device processing assistance, M. Salt: for departmental support, and D. Stern and K. Milnamow for critical reading of the 20. Bai, X, Kim, S, Li, Z Turro, N. J.& Ju, J. Design and synthesis of a photocleavable biotinylated nucleotide for DNA analysis by mass spectrometry. manuscript. The work was supported in part by the National Institute of Health(NIH) Nucleic Acids Res 32, 535-541(2004) rough grant no. ROlEBO08260(M.A R and T.M.F. )Can nstitute for Advanced Research(CIfAR), and Army Research Office(ARO)(W91INF-08-1-0365). This work was 21. Handwerger, R G. Diamond, S L Biotinylated photocleavable lyethylenimine: capture and triggered release of nucleic acids from solid ormed in part at the Cornell Nanoscale Science and Technology Facility, a member c supports. Bioconjug. Chem. 18, 717-723(2007) the National Nanotechnology Infrastructure Network that is supported by the National 23. Olejnik, I et al. Photocleavable biotin derivatives-a versatile approach for the Author contributions ation of biomolecules. Proc. Natl Acad. Sci. USA 92, 7590-7594(1995) E.S. designed the MPC and performed all MPC experiments. E.S. and B RL designed the 24. Vickers, A J, Savage, C, OBrien, M. F.& Lilja, H. Systematic review of MPC fabrication and performed MPC velocity and doubling time as predictors nanosensor fabrication process and E.S.A. V. and BRI performed nanose processing D.J.M. assisted with MPC and experimental design, and data 25. Shariat,S.F,Scardino, P.T.& Lilja, H Screening for prostate cancer. an update. analysis E.S., A V. NKR and J.M.C. performed the sensing measurements E.S. Can.. UroL15,4363-4374(2008) L.M. C and J.P. prepared and analysed the protein samples. E.S., M.A.R. and. ME. wrote 6. Rubach, M. Szymendera, J. J, Kaminska, J. Kowalska, M. Serum the manuscript and edited it, with contributions from all authors. CA 15.3, CEA and ESR patterns in breast cancer. Int. J. Biol. Markers 12, 68-173(1997) Additional information 27. Uehara, M. et aL. Long-term prog study of carcinoembryonic The authors deare competing financial interests: details accompany the paper at ww (CEA)and carbohydrate antigen 15-3(CA 15-3)in breast cancer. Inf. J Clin. Onco.13,47-451(2008) rints and permission infor Ifstrom,N.Karlstrom,A.e.&Linnros,J.Siliconnanoribbonsforelectricalonlineathttp://npgnaturecom/reprintsandpermissions/.Correspondenceandrequestsfor detection of biomolecules. Nano Letf. 8, 945-949(2008) materials should be addressed to M.A.R. and T M.F NaturENanoteChnOlogyIVol5iFebRuaRy2010Iwww.nature.com/naturenanotechnology 2010 Macmillan Publishers Limited. All rights reserved16. Stern, E. et al. Importance of the Debye screening length on nanowire field effect transistor sensors. Nano Lett. 7, 3405–3409 (2007). 17. Zhou, H., Ranish, J. A., Watts, J. D. & Aebersold, R. Quantitative proteome analysis by solid-phase isotope tagging and mass spectrometry. Nature Biotechnol. 20, 512–515 (2002). 18. Templin, M. F., Stoll, D., Bachmann, J. & Joos, T. O. Protein microarrays and multiplexed sandwich immunoassays: what beats the beads? Comb. Chem. High Through. Screen 7, 223–229 (2004). 19. Hermanson, G. T. Bioconjugate Techniques (Elsevier, 1996). 20. Bai, X., Kim, S., Li, Z., Turro, N. J. & Ju, J. Design and synthesis of a photocleavable biotinylated nucleotide for DNA analysis by mass spectrometry. Nucleic Acids Res. 32, 535–541 (2004). 21. Handwerger, R. G. & Diamond, S. L. Biotinylated photocleavable polyethylenimine: capture and triggered release of nucleic acids from solid supports. Bioconjug. Chem. 18, 717–723 (2007). 22. Senter, P. D. et al. Novel photocleavable protein crosslinking reagents and their use in the preparation of antibody–toxin conjugates. Photochem. Photobiol. 42, 231–237 (1985). 23. Olejnik, J. et al. Photocleavable biotin derivatives—a versatile approach for the isolation of biomolecules. Proc. Natl Acad. Sci. USA 92, 7590–7594 (1995). 24. Vickers, A. J., Savage, C., O’Brien, M. F. & Lilja, H. Systematic review of pretreatment prostate-specific antigen velocity and doubling time as predictors for prostate cancer. J. Clin. Oncol. 27, 398–403 (2009). 25. Shariat, S. F., Scardino, P. T. & Lilja, H. Screening for prostate cancer: an update. Can. J. Urol. 15, 4363–4374 (2008). 26. Rubach, M., Szymendera, J. J., Kaminska, J. & Kowalska, M. Serum CA 15.3, CEA and ESR patterns in breast cancer. Int. J. Biol. Markers 12, 168–173 (1997). 27. Uehara, M. et al. Long-term prognostic study of carcinoembryonic antigen (CEA) and carbohydrate antigen 15-3 (CA 15-3) in breast cancer. Int. J. Clin. Oncol. 13, 447–451 (2008). 28. Elfstrom, N., Karlstrom, A. E. & Linnros, J. Silicon nanoribbons for electrical detection of biomolecules. Nano Lett. 8, 945–949 (2008). 29. Cantor, C. R. & Schimmel, P. R. Biophysical Chemistry: Part III: The Behavior of Biological Macromolecules (Freeman, 1980). 30. Homola, J. Present and future of surface plasmon resonance biosensors. Anal. Bioanal. Chem. 377, 528–539 (2003). Acknowledgements The authors would like to thank J. Straight for many helpful discussions, M. Look and J. Bertram for blood samples, M. Power for device processing assistance, M. Saltzman for departmental support, and D. Stern and K. Milnamow for critical reading of the manuscript. The work was supported in part by the National Institute of Health (NIH) through grant no. R01EB008260 (M.A.R. and T.M.F.), Canadian Institute for Advanced Research (CIfAR), and Army Research Office (ARO) (W911NF-08-1-0365). This work was performed in part at the Cornell Nanoscale Science and Technology Facility, a member of the National Nanotechnology Infrastructure Network that is supported by the National Science Foundation (NSF), and at the Yale Institute for Nanoscience and Quantum Engineering. This paper is dedicated to the memory of Alan R. Stern. Author contributions E.S. designed the MPC and performed all MPC experiments. E.S. and B.R.I. designed the MPC fabrication and performed MPC processing. E.S., A.V. and M.A.R. designed the nanosensor fabrication process and E.S., A.V. and B.R.I. performed nanosensor processing. D.J.M. assisted with MPC and nanosensor experimental design, and data analysis. E.S., A.V., N.K.R. and J.M.C. performed the sensing measurements. E.S., J.M.C. and J.P. prepared and analysed the protein samples. E.S., M.A.R. and T.M.F. wrote the manuscript and edited it, with contributions from all authors. Additional information The authors declare competing financial interests: details accompany the paper at www. nature.com/naturenanotechnology. Supplementary information accompanies this paper at www.nature.com/naturenanotechnology. Reprints and permission information is available online at http://npg.nature.com/reprintsandpermissions/. Correspondence and requests for materials should be addressed to M.A.R. and T.M.F. a 1.020 b c d 1.015 1.010 Normalized IDS Normalized IDS 1.005 1.000 0.995 1.020 2.5 ng ml−1 PSA 2.0 ng ml−1 PSA 30 U ml−1 CA15.3 15 U ml−1 CA15.3 1.04 1.03 1.02 1.01 1.00 1.015 1.010 Normalized IDS Normalized IDS 1.005 1.000 0.995 0.99 1.00 1.01 1.02 1.03 1.04 1.05 −50 0 PSA/CA15.3 spiked blood Unspiked control blood PSA PSA/CA15.3 spiked blood Unspiked control blood CA15.3 50 100 150 200 −25 25 50 75 100 125 0 Time (s) −50 0 50 100 Slope ratio = 1.38 Slope ratio = 1.94 150 200 Time (s) Time (s) −25 25 50 75 100 125 0 Time (s) Figure 4 | Label-free sensing. All sensing measurements were performed at VDS ¼ 1 V and VG ¼ –5 V and all sample introductions occurred at t ¼ 0. Normalizations were performed by dividing device currents by the pre-addition (t , 0) current level average. VDS, drain–source voltage. a, Response of an anti-PSA functionalized sensor to a MPC-purified blood sample initially containing 2.5 ng ml21 PSA (and also 30 U ml21 CA15.3), or a control sample containing neither. b, Response of an anti-CA15.3 functionalized sensor to a MPC-purified blood sample initially containing 30 U ml21 CA15.3 (and also 2.5 ng ml21 PSA), or a control sample containing neither. c,d, Normalized response of two anti-PSA (c) and two anti-CA15.3 (d) functionalized devices to MPC-purified blood containing both PSA and CA15.3, with concentrations labelled. A least-squares fit is represented by a solid black line over the selected region (line endpoints). The ratio of the normalized slopes calibrates the ratio of concentrations. LETTERS NATURE NANOTECHNOLOGY DOI: 10.1038/NNANO.2009.353 142 NATURE NANOTECHNOLOGY | VOL 5 | FEBRUARY 2010 | www.nature.com/naturenanotechnology © 2010 Macmillan Publishers Limited. All rights reserved