The Memory Collector by Meg Gardiner

Near the start of Edgar-finalist Gardiner's solid follow-up to The Dirty Secrets Club, San Francisco forensic psychiatrist Jo Beckett examines Ian Kanan, a distressed airline passenger who turns out to be suffering from anterograde amnesia, which makes it impossible for him to form new memories. Kanan, who's sure that his family has been kidnapped and he's been poisoned, disappears from the hospital before Beckett can learn more. When she starts digging into his background, Beckett discovers not only that Kanan was a security consultant for Chira-Sayf, a nanotechnology company, but that he may have been exposed to Slick, an experimental bioweapon. Along with her SFPD contact, Lt. Amy Tang, and para-jumper boyfriend, Gabe Quintana, Beckett races to find Kanan before the people he's pursuing unleash Slick on San Francisco. Gardiner more than compensates for the sometimes implausible plot with her effective use of Kanan's amnesia and her heroine's resourcefulness.