Which structural feature may produce a bathocromic or hypocromic effect in an organic compound.
Answers
The surrounding environment can induce hypsochromic or bathochromic effects as well as hypochromic or hyperchromic effects. In the typical case in molecular spectroscopy, however, the surrounding environment interacts with only one separated fluorescent molecule. The signal that can be obtained from one molecule is relatively low, and many interactions need to occur at the same time in order to obtain a measurable signal. This means the concentration of an interacting molecule (e.g., the analyte) needs to be high to be detected. In the case of CPs, one environmental molecule interacts with many monomer units of the CP due to the conjugated π-system. Therefore, in the case of CPs, the concentration of interacting molecules (e.g., analyte) in the environment can be very low and still lead to a large signal. This phenomenon is referred to as signal amplification in CP-based biosensor devices using optical transducer systems