Luminometer for detecting Bio-Luminescensce

Quick Links on this page:

1. What is Bio-Luminescence?
2. How Bio-Luminescence works?
3. Acknowledgement
4. Details
5. Challenges in measuring Bio-Luminescence using Silicon Photo-diode

We have developed a prototype that can be turned into a portable Luminometer for Bio-Luminescence measurements. The device is very compact and can be made into a low power consumption device suitable for field use for agri, food, pathology and other applications.

What is Bio-luminescence?

Source: Wikipedia
[External Link]

Bioluminescence is the production and emission of light by a living organism. Bioluminescence is a naturally occurring form of chemiluminescence where energy is released by a chemical reaction in the form of light emission.

Fireflies, anglerfish, and other creatures produce the chemicals luciferin (a pigment) and luciferase (an enzyme).The luciferin reacts with oxygen to create light. The luciferase acts as a catalyst to speed up the reaction, which is sometimes mediated by cofactors such as calcium ions or ATP (Adenosine triphosphate). The chemical reaction can occur either inside or outside the cell. In bacteria, the expression of genes related to bioluminescence is controlled by an operon called the Lux operon.

How Bioluminescence works?

Source: howstuffworks.com
[External Link]

Acknowledgement:

Ideas Unlimited developed this for CFTRI (http://www.cftri.com - Central Food and Technological Research Institute, Mysore), for one of their projects to develop a low cost silicon photo-diode based Luminometer, which can detect very low intensity of Bio-Luminescence emitted by biological reactions.

CFTRI is working on Bio-luminescence based applications for detection of food contamination and other applications. In this initiative, as a first step, Ideas Unlimited has conceptualized and designed some prototype setups for experimenting with a silicon photo-diode to sense different bio-luminescence reactions and comparing results generated with lab grade equipment which use more expensive Photo-multiplier tubes.

Details:

A low cost, portable Luminometer, if developed will have tremendous applications in the fields of Agriculture, Food Inspection and Quality Control, Contamination detection, Clinical Pathology and Medical fields.

Experimental setup with Silicon Photo diode and slot to insert sample in a test tube.

Experimental setup optically sealed by the lid befoe measurements.

3d Model of the prototype

Screen shot of the Real time data logging software for Luminometer

Challenges in measuring Bio-luminescence using Silicon Photo-diode

A normal silicon photo diode requires luminance to the tune of micro-watts per centimeter square. However most of the bioluminescence produced is in the order of nano-watts or pico-watts per centimeter square. At these levels a silicon photo diode's junction will not even trigger. A workaround had to be devised to detect such low bioluminescence.