Note an excerpt from the "authoritative" web site author you quoted. He is totally out of touch with modern research, and is not at all active in this area. In addition, his area of expertise is NOT molecular biology at all, so his "authority" on silicon as a basis for life should NOT be relied on.
Look to more recent researchers, and see what they have to say, and you will find that "NO CREDIBLE CURRENT SCIENTIST SUGGESTS SILICON CAN BE THE BASIS FOR ANY ADVANCED LIFE".
Here is the excerpt of your authors present occupation
Around the time I left Manchester I met my future wife and decided to move over to the States. I served as manager of applications software for the supercomputer company Cray Research in Minneapolis for several years, and it was during this time that our two children were born. While at Cray I wrote in my spare time for Astronomy magazine and, in 1982, decided to take the plunge into full-time freelance writing. That's been my occupation ever since, interspersed with lectures, school talks, and travel. We moved back to England (Cumbria) around the time of my career change, spent the next 16 years there, and returned to the U.S. in 1999.
As you note, this man has become a magazine writter, and is not actively involved in any acadamia. This does not disqualify him as an expert per se', but his assertion of silicon as a basis for life, in my book, does.