The image shows Mike Bennet, 57, and wife Julie, 50, from Irby in Wirral, holding hands in a Merseyside hospice.
It was taken shortly before Mr Bennet died on Monday from a brain tumour.
Relatives and friends have launched a fundraising campaign to help the couple's three children, Oliver, 13, Hannah, 18 and Luke 21.
It raised thousands in the first 24 hours.
Friend Sue Wright said: "I told her the community would come together to help look after her kids - and she opened her eyes and smiled."