Using Google Alerts, you can get alerted when your brand (or any search term you choose) is found in a webpage indexed by Google. You have the option to receive these alerts by RSS which you can then, in turn, use to trigger a zap and send to any service you like to notify you.
When setting up your Google Alert, select to receive the alert via "RSS feed" and then click the RSS icon to get your RSS feed URL.
You then input that URL in the trigger of the zap:
In our sample zap, we're sending the details of the alert to a Slack channel, but you can swap this out for any other service you prefer: