Investigation of novel quantum dots/proteins/cellulose bioconjugate using NSOM and photoluminescence

Peng Zhang, Shi You Ding, Qi Xu, Steve Smith, Garry Rumbles, Michael E. Himmel

Research output: Contribution to journalConference articlepeer-review


We investigated the engineered bioconjugate of cadmium selenide core/zinc sulfide shell, (CdSe)ZnS, quantum dots (QDs) with genetically modified proteins using near-field scanning optical microscopy (NSOM). A genetically engineered protein polymer was expressed and purified from E. coli. The protein polymer was allowed to serf-assemble to the bacterial microcrystalline cellulose surface through the cellulosic binding domain. QDs were then conjugated to the protein/cellulose assembly through interaction with the oxhistidine tag on the protein. The transmitted near-field optical signals are collected and detected by both a PMT (near-field scanning optical microscopy, NSOM) and a spectrometer (near-field scanning optical spectroscopy, NSOS). Results from the sample containing the QDs/protein/cellulose assemblies suggest that QDs were arrayed along the cellulose surface. The near-field spectroscopic study also showed that the slight change of spectroscopic properties of the QDs upon bioconjugation, indicating the strong interaction between the constructed protein and QDs.

Original languageEnglish
Article numberA-41
Pages (from-to)137-144
Number of pages8
JournalProceedings of SPIE - The International Society for Optical Engineering
Publication statusPublished - Dec 1 2004
EventPhysical Chemistry of Interfaces and Nanomaterials III - Denver, CO, United States
Duration: Aug 3 2004Aug 6 2004

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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