Navigation Links
Model is first to compare performance of 'biosensors'
Date:1/3/2008

WEST LAFAYETTE, Ind. - Researchers have developed a new modeling technique to study and design miniature "biosensors," a tool that could help industry perfect lab-on-a-chip technology for uses ranging from medical diagnostics to environmental monitoring.

The experimental devices represent a new class of portable sensors designed to capture and detect specific "target molecules," which will allow the sensors to identify pathogens, DNA or other substances.

Now researchers at Purdue University are the first to create "a new conceptual framework" and corresponding computational model to relate the shape of a sensor to its performance and explain why certain designs perform better than others, said Ashraf Alam, a professor of electrical and computer engineering.

Findings also refute long-held assumptions about how to improve sensor performance.

The researchers tested and validated their model with experimental data from various other laboratories.

"Many universities and companies are conducting experiments in biosensors," Alam said. "The problem is that until now there has been no way to consistently interpret the wealth of data available to the research community. Our work provides a completely different perspective on how to analyze their data and how to interpret them."

Research findings are detailed in a paper that appeared in the Dec. 21 issue of the journal Physical Review Letters. The paper was written by electrical and computer engineering doctoral student Pradeep Nair and Alam.

Biosensors integrate electronic circuitry with natural molecules, such as antibodies or DNA, which enable the devices to capture target molecules. In efforts to design more sensitive devices, engineers have created sensors with various geometries: some capture the biomolecules on a flat, or planar surface, others use a single cylindrical nanotube as a sensing element, and others use several nanotubes, arranged in a crisscrossing pattern like overlapping sticks.

Researchers have known for several years that smaller devices are more sensitive than larger ones. Specifically, the most sensitive devices are those built on the scale of nanometers, or billionths of a meter, such as tiny hollow nanotubes made of carbon.

"But we haven't really known why smaller sensors are more sensitive," Alam said.

One obstacle in learning precisely why smaller sensors work better is that the analysis is too computationally difficult to perform with conventional approaches. The Purdue researchers solved this problem by creating a model using a mathematical technique called Cantor transformation, which simplified the computations needed for the analysis.

"That is the most important aspect of this work," Nair said. "You could not effectively analyze the physics behind these biosensors by using brute force with massive computing resources. It either could not be done, or you would not be able to get consistent results."

The new model explains for the first time why a single nanotube performs better than sensors containing several nanotubes or flat planar sensors and refutes the predominant explanation for why smaller sensors work better than larger ones.

"Everyone presumes that the nanometer-scale sensors are better simply because they are closer to the size of the target molecules," Alam said "This classical theory suggests that because larger sensors dwarf the molecules they are trying to detect, these target molecules are just harder to locate once they are captured by the probe. It's like trying to see a small speck on a large surface. But that same target molecule is no longer a speck if it lands on a probe closer to its own size, so it's much easier to see.

"What we found, however, was not that smaller sensors are better able to detect target molecules, but that they are better able to capture target molecules. It's not what happens after the molecule is captured that determines how well the sensor works. It's how fast the sensor actually captures the molecule to begin with that matters most."

The distinction is important for the design of biosensors.

The reason smaller sensors capture molecules more effectively is because using a single nanotube sensor eliminates a phenomenon called "diffusion slow down." As a result, target molecules move faster toward single nanotubes than other structures.

The new model developed by the Purdue researchers determined that "the smaller the better," Alam said.

"This acceleration starts coming in when you make sensors on the size scale of tens of nanometers. That is when you will get a real advantage."

Future work will concentrate on applying the model to the performance of a "fractal sponge," which is a shape containing many pores. Such a shape is important for applications in drug delivery and filtration.


'/>"/>

Contact: Emil Venere
venere@purdue.edu
765-494-4709
Purdue University
Source:Eurekalert

Related biology technology :

1. Model for the assembly of advanced, single-molecule-based electronic components developed at Pitt
2. Pharsight Invited to Present on Oncology Modeling and Simulation at Quantitative Pharmacology Symposium in China
3. United BioSource Acquires Caro Research, Leader in Simulation Modeling
4. NovaQuest Advances Virtual Development Model With Strategic Investment in TOPIGEN Pharmaceuticals
5. CTDC Holds a Ribbon Cutting Ceremony to Showcase First SnO2 Production Line
6. Co-Inventor of Amgens Aranesp(R) Technology Directs Worldwide Patent Strategy for Diffusion Pharmaceuticals First-in-Class Oxygen Enhancing Therapeutics
7. China-Biotics, Inc. Announces Conference Call to Discuss First Quarter FY 2008 Results
8. YM BIOSCIENCES ANNOUNCES NIMOTUZUMAB COLORECTAL CANCER TRIAL FIRST COHORT IS CLOSED TO ACCRUAL
9. USGI Medical Demonstrates First System for Gastrotomy Closure in NOTES
10. AMDLs First Full Service JPGreen Health and Personal Care Center Set to Open in Hangzhou, China
11. Avastin Approved in Europe for First-Line Treatment of Patients With Advanced Kidney Cancer
Post Your Comments:
*Name:
*Comment:
*Email:
(Date:2/10/2016)...  Allergan plc (NYSE: AGN ) a leading ... , Allergan,s CEO and President, will be featured as ... the RBC Capital Markets Healthcare Conference on Tuesday, February ... York Palace Hotel in New York, NY ... can be accessed on Allergan,s Investor Relations web site ...
(Date:2/10/2016)... ... February 10, 2016 , ... SonaCare Medical, LLC reports ... program, Sonalinkā„¢ remote monitoring. The inaugural launch of this new technology occurred over ... Dr. Samuel Peretsman to a HIFU technical expert at SonaCare Medical headquarters. ...
(Date:2/10/2016)... ... February 09, 2016 , ... Creation Technologies, ... of the Highest Overall Customer Rating Award from Circuits Assembly , today announced ... across the USA, Canada, Mexico and China. , The EMS provider, known in ...
(Date:2/9/2016)... ... 2016 , ... Clinovo , the cloud-based eClinical software ... Capture (EDC) system ClinCaptureand its new Contract Research Organization (CRO) Partner Program ... San Mateo, California on February 10th and 11th. Watch 2-min video . ...
Breaking Biology Technology:
(Date:1/25/2016)... , Jan. 25, 2016  Glencoe Software, the world-leading ... and publication industries, will provide the data management solution ... (NPSC). ... Phenotypic analysis measures the ... organisms, allowing comparisons between states such as health and ...
(Date:1/21/2016)... , January 21, 2016 ... to a new market research report "Emotion Detection and ... Others), Software Tools (Facial Expression, Voice Recognition and ... - Global forecast to 2020", published by MarketsandMarkets, ... expected to reach USD 22.65 Billion by 2020, ...
(Date:1/20/2016)... JOSE, Calif. , Jan. 20, 2016 /PRNewswire/ ... developer of human interface solutions, today announced sampling ... controller solution for wearables and small screen applications ... such as printers. Supporting round and rectangular shapes, ... S1423 offers excellent performance with moisture on screen, ...
Breaking Biology News(10 mins):