Thats what I was missing...Thank you!

I modified it a bit to include the space if it exists:

my $var = 'Sensor30';

while (<DATA>) {
    chomp;
    if (/^(>\s*)?\Q$var\E$/) {
    print "MATCH => $_\n";
    }

}

__DATA__
>Sensor30
>FooSensor30
> Sensor30
Sensor300
Sensor30
>Sensor3
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