TY - JOUR
T1 - Electrochemical Beacon Method to Quantify 10 Attomolar Nucleic Acids with a Semilog Dynamic Range of 7 Orders of Magnitude
AU - Tevatia, Rahul
AU - Chan, Alicia
AU - Oltmanns, Lance
AU - Lim, Jay Min
AU - Christensen, Ander
AU - Stoller, Michael
AU - Saraf, Ravi F.
N1 - Publisher Copyright:
© 2021 American Chemical Society.
PY - 2021/12/14
Y1 - 2021/12/14
N2 - Change in the dynamics of single-stranded DNA or RNA probes tethered to an Au electrode on immunospecific binding to the analyte is a versatile approach to quantify a variety of molecules, such as heavy metal ions, pesticides, proteins, and nucleic acids (NAs). A widely studied approach is the electrochemical beacon method where the redox of a dye attached to the probe decreases as its proximity to the underlying electrode changes on binding. The limit of quantification (LOQ) defined by the semilog dependence of the signal on target concentration is in the picomolar range. Here, a method was studied where, by differential reflectivity, multiple reactions were measured on a monolith electrode. An alternative contrast mechanism was discovered, which led to an approach to enhance the LOQ to 10 aM and increase the dynamic range to 7 orders of magnitude using similar probes and binding conditions. Quantitative analysis on sequences with the G-C fraction ranging from 37 to 72% was performed. The approach will allow for the development of a label-free, enzyme-free microarray to detect biomolecules including NAs and proteins on a single electrode at quantification from 10 aM to 0.1 nM with high specificity.
AB - Change in the dynamics of single-stranded DNA or RNA probes tethered to an Au electrode on immunospecific binding to the analyte is a versatile approach to quantify a variety of molecules, such as heavy metal ions, pesticides, proteins, and nucleic acids (NAs). A widely studied approach is the electrochemical beacon method where the redox of a dye attached to the probe decreases as its proximity to the underlying electrode changes on binding. The limit of quantification (LOQ) defined by the semilog dependence of the signal on target concentration is in the picomolar range. Here, a method was studied where, by differential reflectivity, multiple reactions were measured on a monolith electrode. An alternative contrast mechanism was discovered, which led to an approach to enhance the LOQ to 10 aM and increase the dynamic range to 7 orders of magnitude using similar probes and binding conditions. Quantitative analysis on sequences with the G-C fraction ranging from 37 to 72% was performed. The approach will allow for the development of a label-free, enzyme-free microarray to detect biomolecules including NAs and proteins on a single electrode at quantification from 10 aM to 0.1 nM with high specificity.
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U2 - 10.1021/acs.analchem.1c03020
DO - 10.1021/acs.analchem.1c03020
M3 - Article
C2 - 34843203
AN - SCOPUS:85120635914
SN - 0003-2700
VL - 93
SP - 16409
EP - 16416
JO - Analytical Chemistry
JF - Analytical Chemistry
IS - 49
ER -