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4 Ways Keithley’s 4200A-SCS Parameter Analyzer Simplifies DC I-V Characterization of BioFETs

Extensive research and development have been invested in semiconductor-based biosensors because of their low cost, rapid response, and accurate detection. In particular, field effect transistor-based biosensors, or bioFETs, are used in a wide variety of applications such as in biological research, point of care diagnostics, environmental applications, and even food safety.

A bioFET converts a biological response to an analyte and converts that into an electrical signal that can be measured using DC I-V techniques.

A diagram explaining biosensor technology,  a bioFET sensor, and the DC I-V measuring instrument. 

Figure 1: A diagram explaining biosensor technology.

There are a number of ways to conduct DC I-V tests on bioFETs. The easiest way is to use multiple source measure units (SMUs). An SMU is an instrument that sources and measures current and voltage.

Here are 4 ways the Keithley 4200A-SCS Parameter Analyzer can help you easily electrically characterize bioFETs.

1. Integration and Measurement Synchronization of Multiple SMUs

Keithley’s 4200A-SCS Parameter Analyzer combines all the relevant hardware and software you need to conduct DC I-V tests on FET-based biosensors. With automatic synchronization of up to nine SMUs, the parameter analyzer can save significant set-up and configuration time compared to using individual instruments. The parameter analyzer also includes an extensive library of built-in tests for bioFETs and other semiconductor devices and materials. It’s an all-in-one solution that streamlines the testing process, ensures higher accuracy measurements with less room for error, and eliminates the need for external triggering.

2. User-friendly GUI-Based Software

Having an all-in-one DC-IV testing solution for bioFETs is great. But if the process remains complex and unapproachable for engineers who are unfamiliar with DC-IV testing, then having it all in one place doesn’t help them very much. That won’t be a problem with the 4200A-SCS Parameter Analyzer. It comes out of the box with a variety of built-in learning tools including application notes, videos, and training modules that reduce the learning curve for engineers who are less familiar with this application.

The unit also comes with ready-to-use, modifiable application tests that eliminate the need to write new code and save significant time in the test development cycle.

3. Robust Graphing and Analysis Features

Graphing and analysis features in the Keithley 4200A, showing automated line fits on a graph. 

Keithley’s 4200A-SCS Parameter Analyzer allows you to capture real-time measurements, giving you the data you need to characterize bioFETS quickly and easily. But it doesn’t stop with acquiring data, it also helps you visualize it with robust graphing and analysis features. For example, the formulator is a built-in tool that enables you to make calculations on test data, provides automated line fits, and performs parameter extractions.

4. Customizable and Upgradable

The engineers at Keithley designed this parameter analyzer to adapt to the specific needs of your project. Based on the necessary test requirements, you can use the intuitive UI to configure the system for current-voltage measurements, capacitance-voltage measurements, or pulsed I-V measurements as needed.

If at a later date a new project requires new modules, the 4200A-SCS can be upgraded at any time so you can acquire the tools you need when you need them.


BioFETs are an emerging, cutting-edge technology that require a wide range of knowledge and skills to utilize effectively. As the technology continues to advance and grow, having the right tools can improve the testing and validation phase of development with higher accuracy measurements, reduced learning curves, and faster testing cycles. Keithley’s 4200A-SCS Parameter Analyzer is exactly that kind of tool.

If you’d like to explore a more detailed guide to DC-IV characterization of FET-based biosensors, you can check out our application note here. You can also learn more about Keithley’s 4200A-SCS Parameter Analyzer on its product page here.