title: Single-step nanoplasmonic VEGF165 aptasensor for early cancer diagnosis.
abstract: Early cancer diagnosis is very important for the prevention or mitigation of metastasis. However, effective and efficient methods are needed to improve the diagnosis and assessment of cancer. Here, we report a single-step detection method using a nanoplasmonic aptamer sensor (aptasensor), targeting a vascular endothelial growth factor-165 (VEGF(165)), a predominant biomarker of cancer angiogenesis. Our single-step detection is accomplished by (1) specific target recognition by an aptamer-target molecule interaction and (2) direct readouts of the target recognition. The readout is achieved by inactivation of surface plasmon enhancement of fluorescent probes preattached to the aptamers. Our aptasensor provides the appropriate sensitivity for clinical diagnostics with a wide range of linear detection from 25 pg/mL to 25 μg/mL (=from 1.25 pM to 1.25 μM), high specificity for VEGF(165) against PDGF-BB, osteopontin (OPN), VEGF(121), NaCl, and temporal/thermal/biological stability. In experiments with 100% serum and saliva from clinical samples, readouts of the aptasensor and an ELISA for VEGF(165) show good agreement within the limit of the ELISA kit. We envision that our developed aptasensor holds utilities for point-of-care cancer prognostics by incorporating simplicity in detection, low-cost for test, and required small sample volumes.
authors.affiliation: Berkeley Sensor and Actuator Center, Department of Bioengineering, Department of Electrical Engineering and Computer Science, University of California, Berkeley, California 94720, United States.
authors.forename: Hansang
authors.initials: H
authors.lastname: Cho
authors.forename: Erh-Chia
authors.initials: EC
authors.lastname: Yeh
authors.forename: Raghu
authors.initials: R
authors.lastname: Sinha
authors.forename: Ted A
authors.initials: TA
authors.lastname: Laurence
authors.forename: Jane P
authors.initials: JP
authors.lastname: Bearinger
authors.forename: Luke P
authors.initials: LP
authors.lastname: Lee
mesh_terms: D000818:Animals; D052158:Aptamers, Peptide / Q000737:chemistry; D014408:Biomarkers, Tumor / Q000032:analysis*; D045744:Cell Line, Tumor; D055088:Early Detection of Cancer / Q000379:methods*; D006801:Humans; D057054:Molecular Imaging / Q000379:methods; D053758:Nanoparticles / Q000737:chemistry; D009374:Neoplasms, Experimental / Q000378:metabolism / Q000473:pathology*; D020349:Surface Plasmon Resonance / Q000379:methods*; D042461:Vascular Endothelial Growth Factor A / Q000032:analysis*
chemical_list: D052158:Aptamers, Peptide; D014408:Biomarkers, Tumor; C467484:VEGFA protein, human; D042461:Vascular Endothelial Growth Factor A