J.P. Arango, K. Barrientos, M.I. Gaviria, P.l Araque, J. Placido, S. Bustamante, M.E. Londoño, M. Jaramillo
Keywords: biochar, biosensor, BSA, carbon dots
Summary:Colombia is the fourth largest palm oil producer in the world and the first in America, according to the Colombia´s national federation of oil palm cultivators . The cultivation of oil palm is present in 161 municipalities in 21 departments of the country and annually generates about 400,000 tons of waste (around 2% of world production), to which value must be added to contribute to the closing of cycles. In recent years, the use of residual biomass to obtain nanomaterials with diverse applications in areas of health, environment and industry has been intensified . Carbon dots (CDots); fluorescent nanoparticles with size of less than 10 nm, have been produced from residual biomass, and due to properties, such as their easy functionalization and long-term photostability, have been successfully incorporated in the construction of optical biosensors, which are emerging as an alternative to traditional methods for biomolecule detection, gaining strength especially in health areas and being reflected in a growing world market that exceeds USD 22 billion. The present study developed an optical biosensor based on Carbon Dots (CDots) obtained from Elaeis guineensis biochar, for the detection of a model molecule, in this case, Bovine albumin serum (BSA). The CDots had a size of 2.5 ± 0.7 nm determined through a High-Resolution Transmission Electronical Microscopy (HR-TEM), a Z potential of -56.1 ± 2.37 mV and a Quantum yield of 1.69%, with emission and excitation wavelengths of 428 and 320 nm, respectively. As a bioreceptor molecule, the anti-BSA was used and conjugated to the CDots surface using the carbodiimide method. The fluorescence of the CDots was evaluated through a fluorescence spectroscopy and posteriorly modulated using graphene oxide. Finally, the performance of the biosensor was analyzed by evaluating the specificity and sensitivity, where a qualitative biosensor was obtained that detects in a range of 1000 - 10 mg / µL of BSA. With the implementation of this technology, it will contribute to the improvement of the quality of life of Colombian vulnerable populations while contributing to the closing of cycles of the oil palm industry.