Due to the toxicity and its negative impacts on the environment of a synthetic dye used in dye-sensitized solar cell (DSSC), natural dye is a good alternative to it. Unfortunately, natural dye exhibits low performance in the device and in order to improve it, co-sensitization technique is commonly used. But it is important to ensure that the molecule size of the dye attached on the photoanode is compatible with each other. Therefore, a new strategy needs to be studied to develop a new co-sensitization technique that might have the potential in DSSC application where the idea is to attach the second dye through noncovalent interaction with the first dye that is already adsorbed by the photoanode. But, before the dye can be used in DSSC applications, the nature of interaction between the first and the second dye needs to be investigated. In this study, acidified chlorophyllin (derived from chlorophyll) and metallocene (ferrocene, manganocene, and cobaltocene) were chosen and the nature of interaction of acidified chlorophyllin with the metallocene was studied through vibrational analysis. It was discovered that acidified chlorophyllin interacted with ferrocene through weak intermolecular forces, meanwhile it reacted with cobaltocene, causing itself to deprotonate and cobaltocene to oxidize, thus forming ionic interaction. On the other hand, the result suggested that the ligands in manganocene were changed in acidified chlorophyllin–manganocene blend but further studies need to be done to understand its reaction mechanism.