Low Cost, Efficient Dual Signal Amplification for Bioassays


The Integrated Bio-Analytical Systems Laboratory (IBASL), led by Dr. Xiaoshan Zhu, within the University of Nevada, Reno Engineering Department focuses on multi-modality bioimaging and signal amplification for biosensing. Dr. Xiaoshan Zhu has developed a dual signal amplification technique for bioassays using Zinc Sulfide nanoparticles.

Technology Summary

Bioassays are typically conducted to measure the effects of a substance on a living organism and are important for the development of new drugs, detecting cancer, and gauging environmental pollution. Existing methods use Cadmium Selenide (CdSe) or Lead Sulfide (PbS). In addition to being toxic, the conventional methods are also labor intensive, because they require a buffer or reagent purification process. The UNR method consists of zinc-ion release from zinc-sulfite (ZnS) nanoparticle labels and enzyme kinetics activated by the released zinc ions as cofactors. Compared to other conventional signal transduction mechanisms, it adopts fewer toxic nanoparticles and is more environmentally friendly.

The new technique has a higher signal gain or signal/noise ratio, making it more efficient at improving bioassay sensitivity or lowering detection limits. Improving sensitivity or lowering detection limits will promote early detection and increase the detail of the outputs. Due to simple preparation and no enzyme mobilization, the method is easier to operate than traditional methods, with a lower cost. Unlike conventional methods the new technique does not require reagent preparation, which can be expensive and time consuming. This lowers the materials cost as well as the labor cost, and makes the process easier to carry out.

In addition to the advantages of the new technology in existing bioassay application, the developed technique can be used to various assays on microRNAs (MiRNAs). MiRNAs have been identified as key gene regulators, and altered MiRNA expression levels have been implicated as indicators of cancer, cardiac disease, and diabetes. Using the new technology for MiRNA detection has established novel and more functional detection protocols.

Potential Applications

  • Measuring or quantifying cells, proteins, and microRNAs in research labs.

  • Analytical measurements that require higher sensitivity or lower detection limits than conventional methods.

  • Due to ease of use, this method could be marketed in research kits to be sold to labs for small scale research.

  • The developed method is generic for the measurement of many analytes (cells, proteins, and microRNAs). It could cover all markets for the analysis of these analytes.

  • Developing microarrays which could be used for many nucleic acid analyses or screening.


UNR is seeking expressions of interest from parties interested in collaborative research to further develop, evaluate, or commercialize this technology.

IP status

UNR ID# UNR12-028
Patent Pending


MicroRNA detection using magnetic separation and zinc-based nanolabels as signal transducers

Dual signal amplification for bioassays using ion release from nanolabels and ion-activated enzyme kinetics

Patent Information:
For Information, Contact:
April Sferrazzo
Account Tech
University of Nevada, Reno and Desert Research Institute
Xiaoshan Zhu
Chad Cowles