Patent ID: 7816147
Filing Date: 2010-10-19
Classification: G01N

Abstract:
1. A method of detecting the presence of an agent in a sample, comprising the steps of: (a) providing a biosensor comprising plant cells selected for the ability to exhibit a state change upon exposure to the agent, and nutrient media for maintaining the cells in a live condition, wherein the biosensor comprises a receptor layer including the plant cells, the receptor layer being sandwiched between two sheets of the nutrient media; (b) establishing a control state value for the biosensor by measuring one or more optical characteristics of the plant cells in the absence of a sample, the optical characteristics being selected from transmittance and reflectance of light; (c) exposing the biosensor to the sample; (d) measuring the optical characteristics of the plant cells exposed to the sample; and (e) comparing the optical characteristics measured with and without exposure to the sample to determine if a state change has occurred in the plant cells; wherein: the sample comprises air; exposing the biosensor to the sample includes diffusing the sample through the nutrient media to the plant cells; and the state change is a change in rate of cytoplasmic streaming or a change in size of stomata.