Biodegradable photoluminescent polymer (BPLP) which comprises an oligomer synthesized from a multifunctional monomer, a diol, and an amino acid by reacting (i) a multifunctional monomer comprising citric acid or triethyl citrate with (ii) a diol to form a reaction product, and further reacting the reaction product with (iii) an amino acid, wherein the amino acid is linked as a side group to the oligomer backbone. The BPLP of the present invention poses tunable fluorescence emission characteristics and are cell-compatible and biodegradable. The BPLP can serve as both implant materials and bioimaging probes.