Image of DPN-deposited protein features on the ridges of a PDMS stamp

Sensor and Microstructure Functionalization

Overview

Micro and nano sensing devices are used to rapidly detect minute quantities of analytes within very small sample volumes without the need for secondary reporter molecules.  They have demonstrated value for applications in medicine, food safety, environmental science, and defense.  Sensor miniaturization delivers a number of benefits, including a reduction in analyte sample volumes, an increase in the number of targets detected, and improvements in selectivity and sensitivity.  Dip Pen Nanolithography® (DPN®) technology can easily functionalize sub-10 micron sensing areas with chemically or biologically active materials (such as enzymes, antibodies, DNA fragments, or inorganics).  DPN has been proven to successfully functionalize a broad range of sensors, including those based on micro cantilevers, field-effect transistors (FET), nanowires, acoustics, optics, plasmonics and electronics.  NanoInk’s DPN systems can also be used to functionalize microstructures such as microfluidic channels, PDMS structures, plastics, membranes, photomasks and many optical and electronic sensing devices.

Image of DPN "pen" tip functionalizing electrode arrays with a protein solution

Problems, Challenges & Un-Met Needs

Although sensing devices created using traditional fabrication platforms are robust, there are often technical hurdles involved in functionalizing the miniaturized elements - often with multiple materials. Similar difficulties are involved when constructing optical or electronic sensing devices by adding optical or electronic polymers or inorganic materials to specific areas on existing chips in a hybrid process.  Until now, methods for easy, reliable, and multiplexed functionalization of miniaturized sensors have been lacking, yet these methods are necessary to advance into the realm of practical sensing applications.

Benefits of DPN

• Local functionalization of single sensing areas: deposit 50 nm - 10 µm features
  
• Scalable patterning using arrays of “pen” tips: parallel print to multiple sensing areas
  
• Flexible, rapid fabrication with single or multiple materials: simultaneously deposit multiple materials with sub-micron precision without the need for a master
  
• Biocompatible patterning: preserve structural integrity and function of deposited biomaterials
• Local functionalization of only the sensing area - and not any other area: deposit materials at addressable locations

Applications

The NanoInk DPN platform is ideal for functionalizing miniaturized sensing devices for:

• Medical applications, including those that involve the immune response, blood, artificial organs, enzymes, and lactic acid
• Food safety applications, such as analysis of pathogens, toxins, freshness indicators, alcohol, and glucose
• Environmental applications that monitor pollutants and contaminants
• Defense applications, including the detection of explosives and chemical or biological agents 

Application Notes

Biosensor Functionalization
Printing on Prefabricated PDMS Microstructures

Application Brochures

Functionalizing Sensors, Microstructures and Devices Using DPN Technology New!

Publications/References

Yue, M.; Stachowiak, J. C.; Datar, R.; Cote, R.; Majumadar, A. Label-Free Protein Recognition Two-Dimensional Array Using Nanomechanical Sensors, Nano Letters 2008, 8, 520