Short answer: Doyle in the 21st century
In moving Mr. Sherlock Holmes to the contemporary, I (unlike other modernizations) did not attempt to alter his character from Doyle’s original eccentric gentleman. Rather I attempted to preserve and faithfully transcribe the great detective. What changes in his implied history are there (and they are not numerous) arise externally from differences in the state of the world. I did however, gladly borrow imagery from other incarnations of the character, most specifically the recent BBC incarnation; besides the actual ‘images’ used, fans of that show may notice a number of references in the text.
The same principle holds largely true for the associates who were brought into the contemporary with him (largely, not completely, an exception is revealed late in the story). The novel is written in the traditional Doyle fashion of being chronicled by Sherlock’s friend, Dr. John Watson.
Note that no particular knowledge on this score is necessary to understand the novel. If you know that Sherlock Holmes is a famous detective, you know all that the book expects you to know. This information is just for the curious