TY - JOUR
T1 - Tuning the Gold Nanoparticle Colorimetric Assay by Nanoparticle Size, Concentration, and Size Combinations for Oligonucleotide Detection
AU - Godakhindi, Varsha Sanjay
AU - Kang, Peiyuan
AU - Serre, Maud
AU - Revuru, Naga Aravind
AU - Zou, Jesse Minghao
AU - Roner, Michael R.
AU - Levitz, Ruth
AU - Kahn, Jeffrey
AU - Randrianalisoa, Jaona
AU - Qin, Zhenpeng
N1 - Funding Information:
The authors thank Kyryl Zagorovsky from Dr. Warren Chan’s group at University of Toronto for helpful discussions and suggesting the pH-assisted conjugation approach. This study is supported by a Texas Medical Research Collaborative (TxMRC) grant and startup fund from The University of Texas at Dallas (UTD). The authors acknowledge HPC resources from the Texas Advanced Computing Center (TACC) at The University of Texas at Austin, the ROMEO HPC Center hosted by the University of Reims Champagne-Ardenne, and the Extreme Science and Engineering Discovery Environment (XSEDE) which is supported by National Science Foundation grant number ACI-1053575. J.R. thanks the University of Texas at Dallas for supporting his visit at the Z.Q.’s group at UTD.
Publisher Copyright:
© 2017 American Chemical Society.
PY - 2017/11/22
Y1 - 2017/11/22
N2 - Gold nanoparticle (GNP)-based aggregation assay is simple, fast, and employs a colorimetric detection method. Although previous studies have reported using GNP-based colorimetric assay to detect biological and chemical targets, a mechanistic and quantitative understanding of the assay and effects of GNP parameters on the assay performance is lacking. In this work, we investigated this important aspect of the GNP aggregation assay including effects of GNP concentration and size on the assay performance to detect malarial DNA. Our findings lead us to propose three major competing factors that determine the final assay performance including the nanoparticle aggregation rate, plasmonic coupling strength, and background signal. First, increasing nanoparticle size reduces the Brownian motion and thus aggregation rate, but significantly increases plasmonic coupling strength. We found that larger GNP leads to stronger signal and improved limit of detection (LOD), suggesting a dominating effect of plasmonic coupling strength. Second, higher nanoparticle concentration increases the probability of nanoparticle interactions and thus aggregation rate, but also increases the background extinction signal. We observed that higher GNP concentration leads to stronger signal at high target concentrations due to higher aggregation rate. However, the fact the optimal LOD was found at intermediate GNP concentrations suggests a balance of two competing mechanisms between aggregation rate and signal/background ratio. In summary, our work provides new guidelines to design GNP aggregation-based POC devices to meet the signal and sensitivity needs for infectious disease diagnosis and other applications.
AB - Gold nanoparticle (GNP)-based aggregation assay is simple, fast, and employs a colorimetric detection method. Although previous studies have reported using GNP-based colorimetric assay to detect biological and chemical targets, a mechanistic and quantitative understanding of the assay and effects of GNP parameters on the assay performance is lacking. In this work, we investigated this important aspect of the GNP aggregation assay including effects of GNP concentration and size on the assay performance to detect malarial DNA. Our findings lead us to propose three major competing factors that determine the final assay performance including the nanoparticle aggregation rate, plasmonic coupling strength, and background signal. First, increasing nanoparticle size reduces the Brownian motion and thus aggregation rate, but significantly increases plasmonic coupling strength. We found that larger GNP leads to stronger signal and improved limit of detection (LOD), suggesting a dominating effect of plasmonic coupling strength. Second, higher nanoparticle concentration increases the probability of nanoparticle interactions and thus aggregation rate, but also increases the background extinction signal. We observed that higher GNP concentration leads to stronger signal at high target concentrations due to higher aggregation rate. However, the fact the optimal LOD was found at intermediate GNP concentrations suggests a balance of two competing mechanisms between aggregation rate and signal/background ratio. In summary, our work provides new guidelines to design GNP aggregation-based POC devices to meet the signal and sensitivity needs for infectious disease diagnosis and other applications.
KW - cross-linking aggregation
KW - gold nanoparticle
KW - infectious diseases
KW - nanoparticle aggregation
KW - point-of-care (POC) diagnosis
UR - http://www.scopus.com/inward/record.url?scp=85034850094&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85034850094&partnerID=8YFLogxK
U2 - 10.1021/acssensors.7b00482
DO - 10.1021/acssensors.7b00482
M3 - Article
C2 - 28994578
AN - SCOPUS:85034850094
SN - 2379-3694
VL - 2
SP - 1627
EP - 1636
JO - ACS Sensors
JF - ACS Sensors
IS - 11
ER -