Advancing nanostructured porous Si-based optical transducers for label free bacteria detection

Naama Massad-Ivanir, Giorgi Shtenberg, Ester Segal

Research output: Chapter in Book/Report/Conference proceedingConference contributionpeer-review


Optical label-free porous Si-based biosensors for rapid bacteria detection are introduced. The biosensors are designed to directly capture the target bacteria cells onto their surface with no prior sample processing (such as cell lysis). Two types of nanostructured optical transducers based on oxidized porous Si (PSiO2) Fabry-Pérot thin films are synthesized and used to construct the biosensors. In the first system, we graft specific monoclonal antibodies (immunoglobulin G's) onto a neat electrochemically-machined PSiO 2 surface, based on well-established silanization chemistry. The second biosensor class consists of a PSiO2/hydrogel hybrid. The hydrogel, polyacrylamide, is synthesized in situ within the nanostructured PSiO2 host and conjugated with specific monoclonal antibodies to provide the active component of the biosensor. Exposure of these modified-surfaces to the target bacteria results in "direct-cell- capture" onto the biosensor surface. These specific binding events induce predictable changes in the thin-film optical interference spectrum of the biosensor. Our studies demonstrate the applicability of these biosensors for the detection of low bacterial concentrations, in the range of 10 3-105 cell/ml, within minutes. The sensing performance of the two different platforms, in terms of their stability in aqueous media and sensitivity, are compared and discussed. This preliminary study suggests that biosensors based on PSiO2/hydrogel hybrid outperform the neat PSiO2 system.

Original languageEnglish
Title of host publicationNano-Biotechnology for Biomedical and Diagnostic Research
Number of pages9
StatePublished - 2011

Publication series

NameAdvances in Experimental Medicine and Biology


  • Bacteria detection
  • Biosensor
  • Hybrid
  • Hydrogel
  • Optical transducer
  • Porous Si

All Science Journal Classification (ASJC) codes

  • General Biochemistry,Genetics and Molecular Biology


Dive into the research topics of 'Advancing nanostructured porous Si-based optical transducers for label free bacteria detection'. Together they form a unique fingerprint.

Cite this