Try commenting out the serial in your sketch. In my experience serial communication takes time, and I assume you have a short window where the voltage peaks at more than a volt. Or initialize the serial with a stupidly high baud rate.
Edit: even better, you could try this for a faster response time:
void setup(){
digitalWrite(13,0);
pinMode(13, OUTPUT);
}
void loop(){
if(analogRead(A0)>204){ //at ~1V the ADC will read between 204 and 205
digitalWrite(13,1);
delay(100);
digitalWrite(13,0);
}
}