Nikon AF-S 105mm f/2.8G Micro £630/$880
Your Nikon 85mm macro lens is a DX lens, so upgrading to a new FX macro lens would be a sensible choice. The Nikon AF-S 105mm f/2.8G IF-ED VR Micro is reliable and accurate. The wide f/2.8 aperture and Vibration Reduction are both helpful when shooting handheld in natural light, and the internal focusing motor makes the lens discreet. It also works well as a portrait lens.