Abstract: Embodiments of the instant disclosure relate to a delivery vehicle for site-specific and function-specific precision delivery of sub-micron cargo for petroleum recovery. The delivery vehicle includes an outer shell, inner core, channel, functional cargo, and stimulus-responsive polymer. The delivery vehicle is configured to be mixed with a dispersion fluid and injected into a subterranean residual oil zone. The outer shell is negatively charged and includes graphene sheets interlocked together in a manner to form a spherical structure. The channel traverses the outer shell and terminates at the inner core. The functional cargo absorbs petroleum. The stimulus-responsive polymer is externally positioned on the outer shell and is functionally coupled to and selectively blocks the channel. The stimulus-responsive polymer is configured to unblock the channel when a stimulus is received and thereby allows release of the functional cargo from the inner core via the channel into the subterranean residual oil zone.