Related Experiment Video
Updated: Feb 2, 2026

Optical Detection of E. coli Bacteria by Mesoporous Silicon Biosensors
Published on: November 20, 2013
Simple, Fast And Highly Sensitive Detection Of Gram-Negative Bacteria By A Novel Electrical Biosensor
Abstract:
This work presents a rapid, low-cost, highly sensitive and specific capacitive sensor for detection of Gram negative bacteria in a field setting. Recognition of Gramnegative bacteria is based on specific detection of lipopolysaccharides (LPS) by LPS-specific aptamer probe immobilized on electrode sensors. An inhomogeneous AC electric field is applied on sensor electrodes and induces positive dielectrophoresis that attracts LPS particles to the sensor electrodes for rapid detection. The same AC signal is also used to detect the binding reactions occurred on the sensor surface. The AC signal was optimized, and the binding between LPS and the specific aptamer was demonstrated. The detection limit reaches as low as 4.9 fg/mL for free LPS molecules and 53 #/mL of bacteria within a 30s' response time, meeting the needs of onsite bacteria detection.
Related Concept Videos
Gram-negative Bacterial Protein Secretion Systems
Sputum Studies I: Gram Stain, cytology, and Acid-fast smear and culture
Gram Stain
The Gram Stain is an integral part of sputum studies. It involves the staining of sputum, which permits...
Gene Evolution - Fast or Slow?
In contrast, regions which code...
Negative Regulator Molecules
Positive, Negative, and Zero Work
Fast Fourier Transform
The computational efficiency of the FFT becomes...

