Theranostics 2018; 8(5):1449-1457. doi:10.7150/thno.22540 This issue

Research Paper

D-alanyl-D-alanine-Modified Gold Nanoparticles Form a Broad-Spectrum Sensor for Bacteria

Xinglong Yang1,2,3,5, Yan Dang4, Jinli Lou4, Huawu Shao2✉, Xingyu Jiang1,3✉

1. CAS Center for Excellence in Nanoscience, CAS Key Lab for Biological Effects of Nanomaterials and Nanosafety, Beijing Engineering Research Center for BioNanotechnology, National Center for NanoScience and Technology, ZhongGuanCun BeiYiTiao, Beijing, 100190, China
2. Natural Products Research Center, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, Sichuan, 610041, China
3. University of Chinese Academy of Science, Beijing, 100049, China
4. Department of Clinical Laboratory, Beijing You'an Hospital Affiliated to Capital Medical University, No. 8 You'an Men Wai Xi TouTiao, Fengtai District, Beijing, 100069, China
5. Present address: School of Chemistry and Chemical Engineering, University of Jinan, Jinan 250022, China

This is an open access article distributed under the terms of the Creative Commons Attribution (CC BY-NC) license ( See for full terms and conditions.
Yang X, Dang Y, Lou J, Shao H, Jiang X. D-alanyl-D-alanine-Modified Gold Nanoparticles Form a Broad-Spectrum Sensor for Bacteria. Theranostics 2018; 8(5):1449-1457. doi:10.7150/thno.22540. Available from

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Graphic abstract

Rationale: Rapid and facile detection of pathogenic bacteria is challenging due to the requirement of large-scale instruments and equipment in conventional methods. We utilize D-amino acid as molecules to selectively target bacteria because bacteria can incorporate DADA in its cell wall while mammalian cells or fungi cannot.

Methods: We show a broad-spectrum bacterial detection system based on D-amino acid-capped gold nanoparticles (AuNPs). AuNPs serve as the signal output that we can monitor without relying on any complex instruments.

Results: In the presence of bacteria, the AuNPs aggregate and the color of AuNPs changes from red to blue. This convenient color change can distinguish between Staphylococcus aureus (S. aureus) and methicillin-resistant Staphylococcus aureus (MRSA). This system can be applied for detection of ascites samples from patients.

Conclusion: These D-amino acid-modified AuNPs serve as a promising platform for rapid visual identification of pathogens in the clinic.

Keywords: gold nanoparticles, D-amino acid, bacteria, spontaneous bacterial peritonitis, colorimetric biosensor