"E-DNA" sensors, reagentless, electrochemical biosensors that perform well even when challenged directly in blood and other complex matrices, have been adapted to the detection of a wide range of nucleic acid, protein and small molecule analytes. Here we present a general procedure for the fabrication and use of such sensors.
Total time
~4-6 hours (sensor fabrication and testing per batch)
Steps
1
Prepare chemically modified probe DNA
Synthesize or obtain probe DNA sequences with chemical modifications required for sensor immobilization. Prepare stock solutions at appropriate concentrations for subsequent electrode functionalization.
▶ 01:28
2
Prepare electrochemical sensor electrode
Clean and functionalize electrode surfaces, immobilize modified probe DNA through chemical bonding, and establish stable sensor baseline. Verify proper DNA orientation and coverage on electrode.
▶ 02:48
3
Test sensor for DNA target detection
Apply DNA analyte samples to prepared sensors and measure electrochemical response. Establish dose-response curves and validate detection specificity and sensitivity.
▶ 05:30
4
Test sensor for antibody protein detection
Challenge sensors with antibody or protein analyte samples and record electrochemical signals. Evaluate sensor performance in protein detection mode.
▶ 07:57
5
Test sensor for small molecule detection
Apply small molecule analytes to sensors and measure electrochemical response. Validate reagentless detection capability across molecular weight classes.
▶ 09:47
6
Analyze and interpret representative results
Review electrochemical data outputs, response curves, and comparative performance metrics across different analyte classes. Evaluate sensor efficacy in complex matrices.
▶ 11:24