Abstract: The present disclosure relates to sustainable and green polylactic acid-based membranes embedded with self-assembled positively and negatively charged multiwalled carbon nanotube/graphene oxide nanohybrids for the removal of organic and inorganic nutrients from wastewater, and methods of synthesis of the same. A positively charged multi-walled carbon nanotube/graphene oxide (f-MWCNT/GO) nanohybrid-based mixed matrix membrane can comprise a self-assembled multi-walled carbon nanotube and graphene oxide (f-MWCNT/GO) nanohybrid, and a polylactic acid (PLA) membrane matrix. The f-MWCNT/GO nanohybrid is integrated into the PLA membrane matrix to form the positively charged mixed matrix membrane. A negatively charged multi-walled carbon nanotubes (f-GO/MWCNTs-COOH) nanohybrid-based mixed matrix membrane can comprise a positively charged Graphene Oxide and negatively charged multi-walled carbon nanotube-COOH (f-GO/MWCNTs-COOH) nanohybrid, and a polylactic acid (PLA) membrane matrix.

Abstract: In some embodiments, a method includes applying an analyte to a rGO biosensor configured to bind to the analyte; applying a DC voltage to the rGO biosensor, wherein the DC voltage is +0.0008V to +0.005V for a negatively charged analyte; or ?0.005V to ?0.0008 for a positively charged analyte; and monitoring an electrical signal from the rGO biosensor for a response to the analyte.