How do I bold face text1 but not others in a concatenate string?

[Jennifer]

Text 1 is a first name (i.e. Jane)
Text 2 is a last name (i.e. Doe)
I want to concatenate them but have the first name in regular font and the
last name in bold font.

 

[Dave Peterson]

You could use:
=a1 & " " & b1
to concatenate the values in two cells.

But as long as you keep the formula, you can't use character by character
formatting.