Original Article

Citation: Light: Science & Applications (2016) 5, e16176; doi:10.1038/lsa.2016.176
Published online 2 December 2016

Manipulation and detection of single nanoparticles and biomolecules by a photonic nanojet
Open

Yu-Chao Li1,2, Hong-Bao Xin1, Hong-Xiang Lei2, Lin-Lin Liu3, Yan-Ze Li4, Yao Zhang1 and Bao-Jun Li1

  1. 1Institute of Nanophotonics, Jinan University, Guangzhou 511443, China
  2. 2State Key Laboratory of Optoelectronic Materials and Technologies, School of Materials Science and Engineering, Sun Yat-Sen University, Guangzhou 510275, China
  3. 3State Key Laboratory of Microbial Technology, School of Life Sciences, Shandong University, Jinan 250100, China
  4. 4National Engineering Research Centre for Beijing Biochip Technology, Beijing 102206, China

Correspondence: Y Zhang, Email: zhyao5@jnu.edu.cn; BJ Li, Email: baojunli@jnu.edu.cn

Received 30 December 2015; Revised 30 May 2016; Accepted 3 June 2016
Accepted article preview online 7 June 2016

Top

Abstract

Optical methods to manipulate and detect nanoscale objects are highly desired in both nanomaterials and molecular biology fields. Optical tweezers have been used to manipulate objects that range in size from a few hundred nanometres to several micrometres. The emergence of near-field methods that overcome the diffraction limit has enabled the manipulation of objects below 100nm. A highly free manipulation with signal-enhanced real-time detection, however, remains a challenge for single sub-100-nm nanoparticles or biomolecules. Here we show an approach that uses a photonic nanojet to perform the manipulation and detection of single sub-100-nm objects. With the photonic nanojet generated by a dielectric microlens bound to an optical fibre probe, three-dimensional manipulations were achieved for a single 85-nm fluorescent polystyrene nanoparticle as well as for a plasmid DNA molecule. Backscattering and fluorescent signals were detected with the enhancement factors up to ~103 and ~30, respectively. The demonstrated approach provides a potentially powerful tool for nanostructure assembly, biosensing and single-biomolecule studies.

Keywords:

nanoparticles; optical detection; optical manipulation; single biomolecules